MacGui: retain the current storage width and height and use it when unparsing the x264 options.

This is done in calculatePictureSizing as it is called whenever width or height change.



git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5175 b64f7644-9d1e-0410-96f1-a4d463321fa5