MacGui: Audio fixes regarding CoreAudio as default.

MacGui: Audio fixes regarding CoreAudio as default.
- Base Patch by Rodeo, thanks Rodeo!
-- Puts CoreAudo at index 0 in the encoder popup to assure it is selected by default if no preset is applied.
-- Fixes issue where going to AC3 or DTS Passthru then back to aac chose faac even if the old "Use CoreAudo instead of FAAC" pref was in effect.
-- Removes some legacy AVI/OGM Code.
- Additional features added after Base Patch:
-- "Use CoreAudio instead of FAAC" preference is now only applied to the built in presets
--- This change means that a custom preset specifying faac is now respected instead of it being overridden by the previously global preference.
--- Xib description changed accordingly
--- Note this means that previous custom presets that used faac will now use it instead of coreaudio.

git-svn-id: svn://localhost/HandBrake/trunk@3138 b64f7644-9d1e-0410-96f1-a4d463321fa5