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