MacGui: save the preset description, it had been broken after the add preset window refactoring.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6640 b64f7644-9d1e-0410-96f1-a4d463321fa5
libhb: remove hb_job_reset
It is no longer needed by the mac ui


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6641 b64f7644-9d1e-0410-96f1-a4d463321fa5