libhb: enable burn-in of all supported text subtitle formats


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6141 b64f7644-9d1e-0410-96f1-a4d463321fa5
Interop: Added methods to dynamically pull the preset, profile, level and tune values. Replaced encoder-specific fields on EncodingProfile with general fields. Standardized the InteropUtilities conversion function names.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6142 b64f7644-9d1e-0410-96f1-a4d463321fa5
decccsub: fix timestamp of "clear" subtitles

This broke CC passthru and is probably the cause of
https://forum.handbrake.fr/viewtopic.php?f=11&t=29835

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6143 b64f7644-9d1e-0410-96f1-a4d463321fa5