MacGui: set a min size and aligned the “Done” button in the Subtitles Defaults window.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6417 b64f7644-9d1e-0410-96f1-a4d463321fa5
MacGui: when a live preview is cancelled, wait for libhb to end its work before reverting back the hud.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6418 b64f7644-9d1e-0410-96f1-a4d463321fa5