Merge pull request #141 from JGulbronson/master

Added a login tab to the nav bar, so you can login from anywhere on the site
Create a sparse unique index on User.email

Enforce non-None emails to be unique
Support another date format for Quest schedules

Specifically, YYYY/MM/DD
Allow periods in prof names in Quest schedules
Merge pull request #145 from UWFlow/david-fix-quest-schedule-parsing

Fix two issues with Quest schedule parsing
Merge pull request #144 from UWFlow/unique-sparse-index-email

Fix email signup race condition
Update homepage users (over 5000 now!)
Merge pull request #147 from JGulbronson/master

Added a button to load old terms by linking to /onboarding