MacGUI: Varius warnings fixes:
- NSUInteger and NSInteger instead of int (where the Cocoa 64bit api uses them).
- Cast to int when needed because NSInteger on 64bit is defined as long.
- NSURL instead of NSString when possible.
- Replaced some deprecated methods/functions.
- numberWithInteger instead of numberWithInt.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5854 b64f7644-9d1e-0410-96f1-a4d463321fa5