diff --git a/CMakeLists.txt b/CMakeLists.txt
index e2c967a58..2880ce56a 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -383,6 +383,7 @@ set(APP_SOURCES
   src/miscellaneous/iconfactory.cpp
   src/miscellaneous/iofactory.cpp
   src/miscellaneous/autosaver.cpp
+  src/miscellaneous/mutex.cpp
 
   # EXCEPTIONS sources.
   src/exceptions/applicationexception.cpp
@@ -476,6 +477,7 @@ set(APP_HEADERS
   src/miscellaneous/iconfactory.h
   src/miscellaneous/skinfactory.h
   src/miscellaneous/autosaver.h
+  src/miscellaneous/mutex.h
 
   # CORE headers.
   src/core/messagesmodel.h
diff --git a/src/gui/feedmessageviewer.cpp b/src/gui/feedmessageviewer.cpp
index fa270386b..223374ea1 100755
--- a/src/gui/feedmessageviewer.cpp
+++ b/src/gui/feedmessageviewer.cpp
@@ -21,6 +21,7 @@
 #include "miscellaneous/databasefactory.h"
 #include "miscellaneous/systemfactory.h"
 #include "miscellaneous/iconfactory.h"
+#include "miscellaneous/mutex.h"
 #include "core/messagesproxymodel.h"
 #include "core/feeddownloader.h"
 #include "core/feedsmodelfeed.h"
diff --git a/src/gui/feedsview.cpp b/src/gui/feedsview.cpp
index 63ea5e77c..c16837afa 100755
--- a/src/gui/feedsview.cpp
+++ b/src/gui/feedsview.cpp
@@ -26,6 +26,7 @@
 #include "core/feedsmodelrecyclebin.h"
 #include "core/feedsmodelfeed.h"
 #include "miscellaneous/systemfactory.h"
+#include "miscellaneous/mutex.h"
 #include "gui/formmain.h"
 #include "gui/formcategorydetails.h"
 #include "gui/formfeeddetails.h"
@@ -202,8 +203,7 @@ void FeedsView::executeNextAutoUpdate() {
     return;
   }
 
-  // If global auto-update is enabled
-  // and its interval counter reached zero,
+  // If global auto-update is enabled and its interval counter reached zero,
   // then we need to restore it.
   if (m_globalAutoUpdateEnabled && --m_globalAutoUpdateRemainingInterval < 0) {
     // We should start next auto-update interval.
diff --git a/src/gui/formimportexport.h b/src/gui/formimportexport.h
index d3bebf653..cab60cc05 100644
--- a/src/gui/formimportexport.h
+++ b/src/gui/formimportexport.h
@@ -36,6 +36,7 @@ class FormImportExport : public QDialog {
       OPML20 = 0
     };
 
+    // Constructors.
     explicit FormImportExport(QWidget *parent = 0);
     virtual ~FormImportExport();
 
diff --git a/src/gui/formmain.cpp b/src/gui/formmain.cpp
index 606f37754..1475ca50d 100755
--- a/src/gui/formmain.cpp
+++ b/src/gui/formmain.cpp
@@ -21,6 +21,7 @@
 #include "miscellaneous/settings.h"
 #include "miscellaneous/application.h"
 #include "miscellaneous/systemfactory.h"
+#include "miscellaneous/mutex.h"
 #include "miscellaneous/databasefactory.h"
 #include "miscellaneous/iconfactory.h"
 #include "network-web/webfactory.h"
diff --git a/src/miscellaneous/application.cpp b/src/miscellaneous/application.cpp
index 62a6931cd..202b7b20f 100755
--- a/src/miscellaneous/application.cpp
+++ b/src/miscellaneous/application.cpp
@@ -19,6 +19,7 @@
 
 #include "miscellaneous/iconfactory.h"
 #include "miscellaneous/iofactory.h"
+#include "miscellaneous/mutex.h"
 #include "gui/feedsview.h"
 #include "gui/feedmessageviewer.h"
 #include "gui/messagebox.h"
@@ -66,13 +67,20 @@ DownloadManager *Application::downloadManager() {
     m_downloadManager = new DownloadManager();
 
     connect(m_downloadManager, SIGNAL(downloadFinished()), mainForm()->statusBar(), SLOT(clearProgressDownload()));
-    connect(m_downloadManager, SIGNAL(downloadProgress(int,QString)),
-            mainForm()->statusBar(), SLOT(showProgressDownload(int,QString)));
+    connect(m_downloadManager, SIGNAL(downloadProgress(int,QString)), mainForm()->statusBar(), SLOT(showProgressDownload(int,QString)));
   }
 
   return m_downloadManager;
 }
 
+Mutex *Application::feedUpdateLock() {
+  if (m_updateFeedsLock == NULL) {
+    m_updateFeedsLock = new Mutex();
+  }
+
+  return m_updateFeedsLock;
+}
+
 void Application::backupDatabaseSettings(bool backup_database, bool backup_settings,
                                          const QString &target_path, const QString &backup_name) {
   if (!QFileInfo(target_path).isWritable()) {
diff --git a/src/miscellaneous/application.h b/src/miscellaneous/application.h
index a6b057572..b25bddb76 100755
--- a/src/miscellaneous/application.h
+++ b/src/miscellaneous/application.h
@@ -30,7 +30,6 @@
 #include "gui/systemtrayicon.h"
 #include "network-web/downloadmanager.h"
 
-#include <QMutex>
 #include <QList>
 
 #if defined(qApp)
@@ -44,6 +43,7 @@
 class FormMain;
 class IconFactory;
 class QAction;
+class Mutex;
 
 class Application : public QtSingleApplication {
     Q_OBJECT
@@ -99,13 +99,7 @@ class Application : public QtSingleApplication {
     }
 
     // Access to application-wide close lock.
-    inline QMutex *feedUpdateLock() {
-      if (m_updateFeedsLock == NULL) {
-        m_updateFeedsLock = new QMutex();
-      }
-
-      return m_updateFeedsLock;
-    }
+    Mutex *feedUpdateLock();
 
     inline FormMain *mainForm() {
       return m_mainForm;
@@ -178,7 +172,7 @@ class Application : public QtSingleApplication {
     // But of user decides to close the application (in other words,
     // tries to lock the lock for writing), then no other
     // action will be allowed to lock for reading.
-    QMutex *m_updateFeedsLock;
+    Mutex *m_updateFeedsLock;
     QList<QAction*> m_userActions;
     FormMain *m_mainForm;
     SystemTrayIcon *m_trayIcon;
diff --git a/src/miscellaneous/iofactory.cpp b/src/miscellaneous/iofactory.cpp
index 8beaeb902..44ad97dad 100755
--- a/src/miscellaneous/iofactory.cpp
+++ b/src/miscellaneous/iofactory.cpp
@@ -59,76 +59,3 @@ bool IOFactory::copyFile(const QString &source, const QString &destination) {
 
   return QFile::copy(source, destination);
 }
-
-bool IOFactory::removeFolder(const QString& directory_name,
-                             const QStringList& exception_file_list,
-                             const QStringList& exception_folder_list) {
-  bool result = true;
-  QDir dir(directory_name);
-
-  if (dir.exists(directory_name)) {
-    foreach (QFileInfo info,
-             dir.entryInfoList(QDir::NoDotAndDotDot | QDir::System |
-                               QDir::Hidden | QDir::AllDirs | QDir::Files, QDir::DirsFirst)) {
-      if (info.isDir()) {
-        if (!exception_folder_list.contains(info.fileName())) {
-          result &= removeFolder(info.absoluteFilePath(), exception_file_list, exception_folder_list);
-        }
-      }
-      else if (!exception_file_list.contains(info.fileName())) {
-        if (!QFile::remove(info.absoluteFilePath())) {
-          result &= false;
-          qDebug("Failed to remove file \'%s\'.", qPrintable(QDir::toNativeSeparators(info.absoluteFilePath())));
-        }
-        else {
-          result &= true;
-        }
-      }
-    }
-
-    if (dir.entryInfoList(QDir::NoDotAndDotDot | QDir::System | QDir::Hidden | QDir::AllDirs | QDir::Files).isEmpty()) {
-      result &= dir.rmdir(directory_name);
-    }
-  }
-
-  return result;
-}
-
-bool IOFactory::copyFolder(const QString &source, const QString &destination) {
-  QDir dir_source(source);
-
-  if (!dir_source.exists()) {
-    return false;
-  }
-
-  QDir dir_destination(destination);
-
-  if (!dir_destination.exists()) {
-    dir_destination.mkpath(destination);
-  }
-
-  foreach (QString d, dir_source.entryList(QDir::Dirs | QDir::NoDotAndDotDot)) {
-    QString dst_path = destination + QDir::separator() + d;
-    dir_source.mkpath(dst_path);
-    copyFolder(source + QDir::separator() + d, dst_path);
-  }
-
-  foreach (QString f, dir_source.entryList(QDir::Files)) {
-    QString original_file = source + QDir::separator() + f;
-    QString destination_file = destination + QDir::separator() + f;
-
-    if (!QFile::exists(destination_file) || QFile::remove(destination_file)) {
-      if (QFile::copy(original_file, destination_file)) {
-        qDebug("Copied file \'%s\'.", qPrintable(f));
-      }
-      else {
-        qDebug("Failed to copy file \'%s\'.", qPrintable(QDir::toNativeSeparators(original_file)));
-      }
-    }
-    else {
-      qDebug("Failed to remove file \'%s\'.", qPrintable(QDir::toNativeSeparators(original_file)));
-    }
-  }
-
-  return true;
-}
diff --git a/src/miscellaneous/iofactory.h b/src/miscellaneous/iofactory.h
index 6cf54868b..d692ddb99 100755
--- a/src/miscellaneous/iofactory.h
+++ b/src/miscellaneous/iofactory.h
@@ -18,7 +18,6 @@
 #ifndef IOFACTORY_H
 #define IOFACTORY_H
 
-#include <QStringList>
 #include <QCoreApplication>
 
 #if QT_VERSION >= 0x050000
@@ -40,19 +39,12 @@ class IOFactory {
     // Returns system-wide folder according to type.
     static QString getSystemFolder(SYSTEM_FOLDER_ENUM::StandardLocation location);
 
+    // Returns contents of a file.
+    // Throws exception when no such file exists.
     static QByteArray readTextFile(const QString &file_path);
 
     // Copies file, overwrites destination.
     static bool copyFile(const QString &source, const QString &destination);
-
-    // Copy whole directory recursively.
-    // Destination path is created if it does not exist.
-    static bool copyFolder(const QString &source, const QString &destination);
-
-    // Removes directory recursively and skips given folders/files.
-    static bool removeFolder(const QString &directory_name,
-                             const QStringList &exception_file_list = QStringList(),
-                             const QStringList &exception_folder_list = QStringList());
 };
 
 #endif // IOFACTORY_H
diff --git a/src/miscellaneous/mutex.cpp b/src/miscellaneous/mutex.cpp
new file mode 100644
index 000000000..dfe00410d
--- /dev/null
+++ b/src/miscellaneous/mutex.cpp
@@ -0,0 +1,71 @@
+// This file is part of RSS Guard.
+//
+// Copyright (C) 2011-2015 by Martin Rotter <rotter.martinos@gmail.com>
+//
+// RSS Guard is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// RSS Guard is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with RSS Guard. If not, see <http://www.gnu.org/licenses/>.
+
+#include "miscellaneous/mutex.h"
+
+
+Mutex::Mutex(QMutex::RecursionMode mode, QObject *parent) : QObject(parent), m_mutex(new QMutex(mode)), m_isLocked(false)  {
+}
+
+Mutex::~Mutex() {
+  qDebug("Destroying Mutex instance.");
+  delete m_mutex;
+}
+
+void Mutex::lock() {
+  m_mutex->lock();
+  setLocked();
+}
+
+bool Mutex::tryLock() {
+  bool result;
+
+  if (result = m_mutex->tryLock()) {
+    setLocked();
+  }
+
+  return result;
+}
+
+bool Mutex::tryLock(int timeout) {
+  bool result;
+
+  if (result = m_mutex->tryLock(timeout)) {
+    setLocked();
+  }
+
+  return result;
+}
+
+void Mutex::unlock() {
+  m_mutex->unlock();
+  setUnlocked();
+}
+
+void Mutex::setLocked() {
+  m_isLocked = true;
+  emit locked();
+}
+
+void Mutex::setUnlocked() {
+  m_isLocked = false;
+  emit unlocked();
+}
+
+bool Mutex::isLocked() const {
+  return m_isLocked;
+}
diff --git a/src/miscellaneous/mutex.h b/src/miscellaneous/mutex.h
new file mode 100644
index 000000000..3c3c3eff2
--- /dev/null
+++ b/src/miscellaneous/mutex.h
@@ -0,0 +1,56 @@
+// This file is part of RSS Guard.
+//
+// Copyright (C) 2011-2015 by Martin Rotter <rotter.martinos@gmail.com>
+//
+// RSS Guard is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// RSS Guard is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with RSS Guard. If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef MUTEX_H
+#define MUTEX_H
+
+#include <QMutex>
+#include <QObject>
+
+
+class Mutex : public QObject {
+    Q_OBJECT
+
+  public:
+    // Constructors.
+    explicit Mutex(QMutex::RecursionMode mode = QMutex::NonRecursive, QObject *parent = 0);
+    virtual ~Mutex();
+
+    // Main methods.
+    void lock();
+    bool tryLock();
+    bool tryLock(int timeout);
+    void unlock();
+
+    // Identifies if mutes is locked or not.
+    bool isLocked() const;
+
+  protected:
+    // These methods set proper value for m_isLocked and emit signals.
+    void setLocked();
+    void setUnlocked();
+
+  signals:
+    void locked();
+    void unlocked();
+
+  private:
+    QMutex *m_mutex;
+    bool m_isLocked;
+};
+
+#endif // MUTEX_H
diff --git a/src/miscellaneous/settings.h b/src/miscellaneous/settings.h
index 42a938244..9b8990e2f 100755
--- a/src/miscellaneous/settings.h
+++ b/src/miscellaneous/settings.h
@@ -294,7 +294,7 @@ class Settings : public QSettings {
       return m_initializationStatus;
     }
 
-    // Getter/setter for settings values.
+    // Getters/setters for settings values.
     inline QVariant value(const QString &section, const QString &key, const QVariant &default_value = QVariant()) {
       return QSettings::value(QString("%1/%2").arg(section, key), default_value);
     }
diff --git a/src/miscellaneous/systemfactory.h b/src/miscellaneous/systemfactory.h
index d729175c5..aa5fcacaa 100755
--- a/src/miscellaneous/systemfactory.h
+++ b/src/miscellaneous/systemfactory.h
@@ -83,6 +83,7 @@ class SystemFactory : public QObject {
     // Tries to download list with new updates.
     QPair<UpdateInfo, QNetworkReply::NetworkError> checkForUpdates();
 
+    // Checks if update is newer than current application version.
     static bool isUpdateNewer(const QString &update_version);
 
   public slots:
diff --git a/src/network-web/webbrowser.h b/src/network-web/webbrowser.h
index 699c00148..3c3f7266a 100755
--- a/src/network-web/webbrowser.h
+++ b/src/network-web/webbrowser.h
@@ -132,6 +132,8 @@ class WebBrowser : public TabContent {
     void onTitleChanged(const QString &new_title);
     void onIconChanged();
 
+    // User selected any feed from website to add to reader.
+    // This copies feed link to clipboard and triggers "add feed" dialog.
     void addFeedFromWebsite(const QString &feed_link);
 
   signals:
diff --git a/src/network-web/webpage.cpp b/src/network-web/webpage.cpp
index e8c4610e2..6097aafe6 100644
--- a/src/network-web/webpage.cpp
+++ b/src/network-web/webpage.cpp
@@ -74,6 +74,7 @@ bool WebPage::acceptNavigationRequest(QWebFrame *frame,
   QString scheme = request.url().scheme();
 
   if (scheme == "mailto" || scheme == "ftp") {
+    qWarning("Received request with scheme '%s', blocking it.", qPrintable(scheme));
     return false;
   }
 
@@ -85,6 +86,5 @@ bool WebPage::acceptNavigationRequest(QWebFrame *frame,
   }
 
   qDebug("Accepting request '%s'.", qPrintable(request.url().toString()));
-
   return QWebPage::acceptNavigationRequest(frame, request, type);
 }
diff --git a/src/network-web/webview.h b/src/network-web/webview.h
index 2a0c9f12a..3766531d3 100644
--- a/src/network-web/webview.h
+++ b/src/network-web/webview.h
@@ -66,12 +66,11 @@ class WebView : public QWebView {
     void openImageInNewTab();
     void searchTextViaGoogle();
     void saveCurrentPageToFile();
+    void printCurrentPage();
 
     // Provides custom context menu.
     void popupContextMenu(const QPoint &pos);
 
-    void printCurrentPage();
-
   private slots:
     void downloadLink(const QNetworkRequest &request);