All device configuration is now reported from capabilities in the same
way. Therefore it is now possible to generate the .device settings keys
during runtime for all reported modules
NDI, SPOUT and Syphon are able to capture/playback audio.
Decklink audio playback on the other hand is not dependant upon video
playback selection (works as a standalone device).
* use ug --capabilities for querying
* support for webcams on Windows and MacOS
* support for decklink capturers and modes
* query v4l2 through UltraGrid
* don't store state in ui widgets (preparation for saving/loading settings)
* automatic FEC