Applied various Debian patches
    
    - Drop Fedora >= 15 conditionals as older Fedora versions aren't supported any more
    - Don't crash when the system tray manager (like gnome-shell) is restarted
      Patch created by Julien Danjou, http://bugs.debian.org/500880
    - Fix segfault when the Polish translation is used
      Patch created by Przemysław, http://bugs.debian.org/523873