Basic VPX decoding for plMoviePlayer
Delay intro movie playback until after display init.

- Fixes stretched cursor during movie playback.
Fixed slow playing cyan intro by changing the timeformats in plMovieplayer all to milliseconds.
Fix assertion when end of movie is reached
Use libopus for decoding Audio
Make audio work

Includes some reorganization and cleanup
Calculate block alignment properly

*sigh* This happens when you copy the formula from somewhere else... Let's do it correctly now and fix the source in plVoiceChat as well.
Rewrite TrackMgr

Also:
Do not start the video again if it is already playing.
Update files from libwebm
Implement Pause

Also, do not show the plate before there is anything on it.
Fix video size

Scale plate using pixels and limit it to viewport size
Do not play if we don't know the codec
Choose tracks based on language, if possible
Decode the whole audio track on startup
Do not crash when loading videos that exist but are not MKV
Address things pointed out during review
Change code style
Fix strcmp
Merge pull request #458 from Mystler/webm

WebM Movie Player (VP9/Opus)