Add automatic orientation of images

Depending on which way you hold your camera, the JPG image that comes
out might be in any number of 8 different orientations. Some browsers
handle these one way, some another, and at the end of the day it's all a
big mess.

Instead of relying on browsers to handle and display the images, we've
decided to orient them on upload. This will give images the best chance
of being viewed correctly wherever they are shown.