LinGui: Presets and preferences are now stored as plists

LinGui: Presets and preferences are now stored as plists
This will also make saving/restoring the queue much easier.
It's a scary big change.  1400 new lines of code.  Due to efficiencies
of a better desing, 2400 lines of old code also gets refactored
down to 1600. Giving a final net +600 lines.
Along the way, I stumbled across a couple bugs and fixed them.
Chapter list entry would get wedged under certain circumstances.
Pausing encoding didn't display pause message in status bar.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@1662 b64f7644-9d1e-0410-96f1-a4d463321fa5