Changed variable name to be descriptive and not stomp on builtin
Changed default_redirect session behavior

Destroy the session variable after grabbing it from the session. This prevents
leaking the data to other requests.
Cleaned up fallback URL behavior
Bumped version
Update usage docs to clear up confusion about customizing signup

There was some confusion with regards to the the custom
signup view example in that it was called `create_profile`
but it was clearly updating a profile that had already
been created.
Fix a typo left by a previous document update
Updated dependencies to latest versions
Bumped version for next release