MacGui: Remove Target Size as a rate control option as it doesn't really work correct...

MacGui: Remove Target Size as a rate control option as it doesn't really work correctly and should die an overdue death.
- Also rearranged the video quality layout a bit.
- Moved Constant Quality above Average Bitrate
- Moved the entire Video Quality matrix down below frame rate where it belongs.
- Presets are mapped accordingly internally in the macgui code so that they are unchanged across platforms.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@3823 b64f7644-9d1e-0410-96f1-a4d463321fa5