Style password reset

To get the custom template to properly override the stock templates I needed to make sure our app is installed before Django registration. @ahinz changed the app load order in 69f709e, but I talked to him and said it was most likely ok (and more correct) to switch it back.

I also removed some legacy activation templates that are now overridden in the management application. The stale, unstyled overrides were only causing confusion.

 Fixes #710