GafferUI startup : Add access to old `None` enums in Python 2
GafferUI startup : Add access to old `None` enums in Python 2

boberfly/gaffer,hradec/gaffer,hradec/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,boberfly/gaffer,lucienfostier/gaffer,hradec/gaffer,johnhaddon/gaffer,hradec/gaffer,johnhaddon/gaffer,ImageEngine/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,johnhaddon/gaffer,lucienfostier/gaffer,boberfly/gaffer,GafferHQ/gaffer,lucienfostier/gaffer,lucienfostier/gaffer,GafferHQ/gaffer,ImageEngine/gaffer,GafferHQ/gaffer,hradec/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,GafferHQ/gaffer,boberfly/gaffer,ImageEngine/gaffer,andrewkaufman/gaffer