default to build
use cythonise instead of custom commands
windows fix
added resolve_slot and start_time
return None if cannot resolve reference
added walk to SourceClip and component_at_time to Sequence
renamed segement to selected
added more properties to EssenceGroup
added right click menu
display group clips
added still_frame property
added adjust height
more Sequence helper methods
added more sequence methods
added nogil to OpenExistingRead
aquire gil before running callback
add path arg to __init__
return slot created
added TimecodeStream and TimecodeStream12M components
fixed typo