Save images inside the recipe files

Not sure how feasible this is, but I'm thinking that perhaps photos could be saved inside the recipe files.
- It would ensure that if the original image is deleted, recipe manager still has a copy of it. >> nevermind that, recipe-manager already "imports" them into the photos/ folder... though perhaps the second point still stands (don't know because of bug #644506)
- This would allow importing/exporting/sharing them along with the recipe

In this case, images should probably be processed (ie: sized down, to ensure that mom and pop don't save 12 megapixels images in there while we display them at 256x256 or something :)