MacGui: x264 options widget for motion estimation. This is the first widget to use...

MacGui: x264 options widget for motion estimation. This is the first widget to use strings for values instead of numbers, so it's a little wonky. Right now, if you don't have a motion est. value specified, but you do have another option with "me" in the name (like "subME" or "b-fraMEs"), the widget will be unresponsive.

Hopefully I'm not accidentally breaking anything with this commit. Had to revert, update, and rewire some stuff after I tried to commit and realized I'd missed a revision.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@582 b64f7644-9d1e-0410-96f1-a4d463321fa5