Add a new generic rectangle interact class.
I modified the crop plug-in so it uses this class instead.
It will be useful for the CopyRectangle plug-in coming along soon
Add base files for copy rectangle plug-in. Not implemented yet.
Merge branch 'master' of https://github.com/devernay/openfx-misc

Conflicts:
	Misc.xcodeproj/project.pbxproj
Copy rectangle: first implementation
Merge branch 'master' of https://github.com/devernay/openfx-misc
Copy rectangle: handle channels + mix & softness correctly