WIP: Partial feature, cropping images according to their clip region

This feature will take an image which has a clip region, and will allow you to crop it, so the parts outside the clip region are discarded. This can free up a lot of memory, especially if you are copying the image multiple times to arange parts of it.

This feature works, as far as cropping goes, but this feature is not complete. There are two important questions/problems:

• The scaling factor does not like height, specifying width and height scale adjustment results in a squashed image. Using just the width scale, works. But just using the width scale without understanding why, would be wrong. Perhaps it actually needs to use the largest scale factor (which ever is larger)
• The position the image ends up in is wrong. Likely as a result of the translation, the Y axis for the object appears very wrong. The more horizontal the crop, the further down the page the object ends up. The crop must result in an image which is in the same location and size as the original.