Drop support for Django 1.6, so I can use migrations
Add a couple more things to do
Fix inadvertently unclosed tag
Punting on favouriting from the album screen
Moving view files into modules
We still need Django 1.6 really, because of sorl-thumbnail

I think we can bump the version of sorl-thumbnail we require
here, but need to check that.
Split up the photos module

This hopefully makes it less confusing to see what depends
on what.
Indicate favourite photos just via the icon

This reduces the number of places that need updating if I
make favouriting happen via XHR.
Moving the onkeydown handler registration into the onload handler

This hopefully makes it less likely that I'll remove it by
accident.
Breaking out the favourite button to its own template
Allow favouriting/unfavouriting via XHR
Reducing code duplication

We'll probably end up having a bunch of places that will
submit forms via XHR, so let's have a function for that,
instead of copy-pasting.
Renaming a view to make it more obvious that it makes changes
Adding a missing semi-colon
Splitting up the photo views further
Refactor the (un)favouriting views

Previously, the favouriting/unfavouriting views responded
with the HTML for the favouriting/unfavouriting buttons, now
it just replies with "OK", and a separate HTTP fetch puts
the correct buttons in place.
Disabled form inputs on form submission
Whitespace tidy
Moving favourites URLs to their own module
Moving favourites tests to reflect URL structure