Make photo save more flexible.

Make uploaded photo saving work whether we pass in a FileStoreage or a
StringIO instance.  Just don't rely on FileStorage.save() - save the
file manually.
Add [0..100] bound check to Notes coordinate set.
Add a proper 'url' field to user model.

Also add a 'real_name' and flickr_auth and flickr placeholder fields to
user, while we're in here.  user.url is auto-generated on creation from
the user.name (screen name, account name, whatever you want to call it).
Use user.url for all user related URL generation.
Flickr Import!!

Add full support for importing photos from Flickr into Brickr.  Includes
every bit of metadata that Flickr stores, except for set & collection
info (which don't exist in Brickr yet), and group pool.  This adds a
simple textbox to user's landing page: paste in a Flickr photo ID then
bam, magic.

Includes new option for users creating an account to authenticate with
Flickr during registration.  This must be done for flickr import to
work.