More tweaks to the homepage
Change login process to be school-independent
Significant changes to user system
Add nprogress.js
More changes to a lot of things

I'm doing really bad at writing commit messages :-/
Only load the correct DefaultEvents
More copy tweaks and such
Add sandbox resetting rake task

And a bunch of `dependent: :destroy`s so that most things will get
cleaned up when they don't make sense to keep around anymore.