Use unicode option when replacing non-words

Fixes #513

src/collection/collectionmodel.cpp

@@ -1442,7 +1442,7 @@ QString CollectionModel::SortText(QString text) {
   else {
     text = text.toLower();
   }
-  text = text.remove(QRegularExpression("[^\\w ]"));
+  text = text.remove(QRegularExpression("[^\\w ]", QRegularExpression::UseUnicodePropertiesOption));
 
   return text;
 

src/context/contextalbumsmodel.cpp

@@ -367,7 +367,7 @@ QString ContextAlbumsModel::SortText(QString text) {
   else {
     text = text.toLower();
   }
-  text = text.remove(QRegularExpression("[^\\w ]"));
+  text = text.remove(QRegularExpression("[^\\w ]", QRegularExpression::UseUnicodePropertiesOption));
 
   return text;
 

src/playlist/playlistmanager.cpp

@@ -234,7 +234,7 @@ void PlaylistManager::SaveWithUI(int id, const QString &playlist_name) {
   QString filter = settings.value("last_save_filter", parser()->default_filter()).toString();
 
   QString suggested_filename = playlist_name;
-  suggested_filename.replace(QRegularExpression("\\W"), "");
+  suggested_filename.replace(QRegularExpression("\\W", QRegularExpression::UseUnicodePropertiesOption), "");
 
   qLog(Debug) << "Using extension:" << extension;