Merge pull request #113 from robotmay/locales

As the cat's out of the bag, add French to footer
Adds an action for sharing photos elsewhere with a public cache

This is targetted towards high traffic from places like Reddit.
By using a short URL, e.g. /p/104, or appending /share to the photo's
standard URL, we can use a different action which can be cached for everyone.

An improvement to this will be to asyncronously load the user's correct
nav if they're signed in. At the moment it's cached as a signed-out user.
Add better sharing options to views
Merge pull request #116 from robotmay/share-caching

Add better sharing support and other fixes.
Latest locale updates
Merge pull request #117 from robotmay/locales

Latest locale updates