Issues that need to be fixed for 17.12 release:
[ ] copy / paste - in progress
[ ] project duration
[ ] composition : move a_track correctly
[ ] geometry keyframes (transform,etc)
[ ] slowmotion effect - in progress
[ ] fix adding clip in bin (corruption with color clip id because of unfinished porting to new method)
[ ] split audio
[ ] define target track (audio/video) for operations