Beta 6 - Nov 2017

Big features:

• Sequence renamed to Track
• CDL support in CMX EDL adapter
• Added otiostat validation utility
• Added Avid Log Exchange (ALE) adapter
• Text burn-in adapter via ffmpeg (thanks @repsac)

Small features:

• Adapters can take arguments
• Improved nested track support in otioview
• Improved API for dealing with parent/child time ranges.