libhb: fix a couple of problems with subtitle merging
I did not handle cases where it was impossible to determine the
stop time properly.

I also did not handle the last subitle properly.  It would have been lost.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5635 b64f7644-9d1e-0410-96f1-a4d463321fa5
libhb: handle zero length EOF subtitle properly


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5636 b64f7644-9d1e-0410-96f1-a4d463321fa5
WinGui: Fix to the Drive Menu service so that it doesn't refresh when clicking on a menuitem.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5637 b64f7644-9d1e-0410-96f1-a4d463321fa5