Add automatic rotation of images that contain orientation data

[runfalk]

I have added automatic rotation when decoding a RawImage. Right now it is implemented as a separate image operation rather than being part of the demosaic step. I have experimented with in-situ rotation vs creating a new OpBuffer and found creating a new one to be more performant due to that it is easy to use rayon's parallell iterators.

Criticism is welcome.

[runfalk]

All right. I have changed things around and put orientation onto the Camera object as well. Since we are now cloning them, I reworked the explicit lifetime 'a for them. The ok_image, RawImage and their likes now consumes a Camera instance instead of holding onto a reference.

I think this is a better solution since explicit lifetimes can be avoided, though I don't know what the original intention behind passing a reference around was.

[pedrocr]

From the conversion we just had on IRC this is probably ready to merge once the whitespace changes are fixed. Do you have anything else you want to fix before I merge?

[runfalk]

I've squashed all changes to a single commit that doesn't modify whitespace. I'm all for merging this and make other improvements in other pull requests.