Starting work on bug #9: removing image container.
Bug #9: adding images table.
Bug #9: dropping thumbnail_url columns.
Bug #9: adding thumbnail_id columns.
Renaming Image to RemoteImage.
Adding FastImage gem.
Adjusting whitespace.
Storing remote image metadata. Fixes bug #9.

Other changes:

* Adding RemoteImage class
* Rescuing fewer exceptions (so they end up in Airbrake)
* Not rescuing exceptions in development (for easier debugging)