OIIOResize: bug fix - must ask for full RoI
OIIOResize: readability
OIIOResize: support alpha
OIIOText: readability
GenericReader: readability
ReadFFmpeg: bug fix - only fill renderWindow
RunScript: does not support render scale
GenericWriter: The effect requires full images to render any region
OCIO*: use kSupports* defines
OIIOResize: fix getRegionsOfInterest