Don't copy default themes to user folder

It's just wasting space in the profile folder, and now with profiles you
will get extra copies which you don't need.  Also makes it hard for us
to update "core" themes if they are in the users profile folder.

src/core/qgsapplication.cpp

@@ -432,7 +432,17 @@ QString QgsApplication::defaultThemePath()
 }
 QString QgsApplication::activeThemePath()
 {
-  return userThemesFolder() + QDir::separator() + themeName() + QDir::separator() + "icons/";
+  QString usersThemes = userThemesFolder() + QDir::separator() + themeName() + QDir::separator() + "icons/";
+  QDir dir( usersThemes );
+  if ( dir.exists() )
+  {
+    return usersThemes;
+  }
+  else
+  {
+    QString defaultThemes = defaultThemesFolder() + QDir::separator() + themeName() + QDir::separator() + "icons/";
+    return defaultThemes;
+  }
 }
 
 QString QgsApplication::appIconPath()
@@ -630,7 +640,7 @@ void QgsApplication::setUITheme( const QString &themeName )
 
 QHash<QString, QString> QgsApplication::uiThemes()
 {
-  QStringList paths = QStringList() << userThemesFolder();
+  QStringList paths = QStringList() << userThemesFolder() << defaultThemesFolder();
   QHash<QString, QString> mapping;
   mapping.insert( QStringLiteral( "default" ), QLatin1String( "" ) );
   Q_FOREACH ( const QString &path, paths )
@@ -1298,7 +1308,6 @@ bool QgsApplication::createThemeFolder()
     myDir.mkpath( folder );
   }
 
-  copyPath( defaultThemesFolder(), userThemesFolder() );
   return true;
 }