Native image rotation

[Alan Third]

I’ve attached a couple of patches. The second renames image scaling to
image transforms, as it covers more than just scaling.

It should be trivial to add cropping now. I can’t think of anything
else we might want to support.

Again I’ve not handled Windows, but hopefully it’s quite
straight‐forward.

The image rotation code is very explicit in what it’s doing and could
be optimized, but I’m not sure it matters.
-- 
Alan Third

0001-Add-native-image-rotation.patch
Description: Text document

0002-Rename-image-scaling-to-image-transforms.patch
Description: Text document