LinGui: Fix title numbers in auto destination filename


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6286 b64f7644-9d1e-0410-96f1-a4d463321fa5
LinGui: protect against possible divide by 0


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6287 b64f7644-9d1e-0410-96f1-a4d463321fa5