add Serbian translator

THANKS

@@ -280,6 +280,7 @@ Pierre-Luc Beaudoin - Vorbis 9 channels patch, Jack input fixes.
 Pierre Marc Dumuid <pierre.dumuid at adelaide dot edu dot au> - Playlist patches
 Pierre Ynard <linkfanel at yahoo dot fr> - WinCE and win32 fixes
 Pittayakom Saingtong <develop5 qt datawiz dot co dot th> - Thai localisation
+Predrag Ljubenović <predragljubenovic@gmail.com> - Serbian localisation
 Przemyslaw Fiala <bl4 a playker dot info> - MMS/TCP fix
 Régis Duchesne <regis at via.ecp.fr> - original VLC code
 Remco Poortinga <poortinga at telin.nl> - IPv6 multicast patch