Refactor video encoding (Add support for mkv)

[stevenhoving]

Currently there is only seems to be a avi muxer. Conversions to other formats would be done by a external converter. If the comments in the avi muxer implementation are still relevant then it has a limit for 4gb files.

• [x] Pull in ffmpeg dependecy.
• [x] write video codec wrapper.
• [x] write format (muxer) wrapper.
• [x] write ffmpeg camcodec encoder.
• [x] update ui.

[stevenhoving]

in progress

[stevenhoving]

Video encoder wrapper is finished. Now working on ui integration for the settings.

[stevenhoving]

Ui video settings dialog is finished.

[stevenhoving]

Finished