AnimationEditor : add curve editor with controls for time, value, interpolation
AnimationEditor : add curve editor with controls for time, value, interpolation

ref #4418

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