- No longer validate the region, so it's now up to the user to get it right (this way we don't have to keep in sync with Amazon every time they add regions)
- Save files into a different directory structure, e.g. '2015/08/03/5bccfdd8-0de2-4efc-b3f3-f4e96bcc4afa/file.png' rather than '2015/08/03/12/03/24/492/file.png'. This does not affect any functionality and won't break any of your old content! It's just more robust. (df7453a0)