Submerge 3.3

- FFmpeg updated to the 3.0 "Einstein" release.
- Now using AVFoundation for H.264 playback in MP4, M4V and MOV containers.
- Hardware decoding of H.264 in MP4, M4V and MOV containers automatically handled by AVFoundation.
- Now possible to export videos without an audio track.
- Fixed some visual glitches in the full screen HUD.
- Fixed a bug that could cause a crash on malformed metadata.