WinGui: Few minor UI tweaks.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5984 b64f7644-9d1e-0410-96f1-a4d463321fa5
MacGui: fixy a crash when opening an external SRT file.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5985 b64f7644-9d1e-0410-96f1-a4d463321fa5
LinGui: fix more damage caused by glade

and reformat some tooltips since gtk3 seems to not do
automatic wrapping of tootips.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5986 b64f7644-9d1e-0410-96f1-a4d463321fa5
LinGui: fix some trailing white space


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5987 b64f7644-9d1e-0410-96f1-a4d463321fa5