Add Twitter icon.

data/data.qrc

@@ -282,6 +282,7 @@
         <file>providers/mtvmusic.png</file>
         <file>providers/cdbaby.png</file>
         <file>providers/echonest.png</file>
+        <file>providers/twitter.png</file>
         <file>lumberjacksong.txt</file>
         <file>schema/schema-18.sql</file>
         <file>star-off.png</file>

src/songinfo/twitterartistinfo.cpp

@@ -17,6 +17,7 @@
 
 #include "twitterartistinfo.h"
 
+#include <QIcon>
 #include <QXmlStreamWriter>
 
 #include <echonest/Artist.h>
@@ -198,6 +199,7 @@ void TwitterArtistInfo::UserTimelineRequestFinished(
   data.type_ = CollapsibleInfoPane::Data::Type_Biography;
   data.id_ = "twitter/" + twitter_id;
   data.title_ = QString("Twitter (%1)").arg(twitter_id);
+  data.icon_ = QIcon(":providers/twitter.png");
 
   QString html = GenerateHtmlForTweetStream(result.toList());