Travis: Update gcc to 4.7

Fixes Travis builds currently failing with:
  cc1plus: error: unrecognized command line option ‘-std=c++11’
Fix notification icon not appearing in Unity

Unity's indicator expects certain properties to be exported by an
application, of which Quassel is lacking some. This adds IconThemePath,
Menu, ItemIsMenu to org.kde.StatusNotifierItem.

Thanks a lot to shiznix for providing this patch.

Fixes #1269
c++11 - from feint to fact

By extending CMAKE_CXX_FLAGS twice for gcc, we kept -ansi which
overrides -std=c++11. Cleaned that up a little.
Merge pull request #86 from seezer/c++11

c++11 - from feint to fact
Fix MainToolBar visibility not saving in OSX

The current code, although completely valid, doesn't work due to moc not
seeing built in defines. See;
https://bugreports.qt-project.org/browse/QTBUG-34593
Merge pull request #87 from denizt/moc

Fix MainToolBar visibility not saving in OSX
Merge remote-tracking branch 'origin/master' into frickel