MacGUI: refactor PictureController. kill a bit of dead code (~500 lines), switch some ivars to properties, hide the private methods and rework the deinterlace logic. Plus UI alignment.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5869 b64f7644-9d1e-0410-96f1-a4d463321fa5