Partial fix of availability module test

We now have both teach and manage versions of AvailabilityModule, and the
test code expects the teach one.
Fix display of cancelled class sections

We recently changed class cancellation to unschedule any cancelled
sections in order to free up times and rooms.  This means that the
'cancelled classes by time' printable can no longer filter out unscheduled
sections when determining which are cancelled.
Remove teacherinfo from programprintables tests

This view was removed along with the remote teacher profile module in
ca4b4113 so we shouldn't be testing it anymore.
Fix QSD caching bug

Our render_qsd template tag was accepting an optional argument 'user'.
This meant that it was possible for the cache to not be flushed properly
because the key set being deleted didn't match the value of the 'user'
argument that was originally used when the cached HTML was rendered.  We
aren't using the user anyway because edit permissions are handled by
Javascript, so there are no side effects to removing this.  See also
9ad33326.
Add confirm_email to AccountCreationTest

We recently made the account creation forms ask for the e-mail address
twice in order to reduce the number of typos.  This commit updates
AccountCreationTest to provide the e-mail address twice when it submits
the form, in order to avoid unexpected behavior.