Fix bug when 'username' can no longer be found in users table
Merge branch 'master' of gh:xtfc/pyboard2
Add a (largely dummy) admin module to courses

When you're the appropriate rank, of course.
Remove unnecessary import

@philipdexter only need to import things here that affect the how the app
should be executed; ie `views` adds all the routes, so it must be imported here
`mail` doesn't affect anything and just provides a new function, so its import
can be relegated to the modules that need it
Add titles for each course level