Interop: Various fixes/improvements
* Exposed container list and changing compatible containers from an enum to an int to allow pulling the container list dynamically.
* Removed a few unused and out-of-date functions and structs.
* Updated a few structs to better track with the QSV changes.
* Added a method to create a pointer to a UTF-8 encoded string.
* Dither now is chosen automatically rather than turned off, which helps with FDK AAC.
* Fixed unicode custom chapter names.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5782 b64f7644-9d1e-0410-96f1-a4d463321fa5