Convert all text subtitles to ASS subs
Add support for font color to tx3g.
Allow more than one style flag at time in tx3g.
Add positioning support to CC subs


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6163 b64f7644-9d1e-0410-96f1-a4d463321fa5