Move a helper to the helpers module.

Change-Id: Ic467243c9edb6e7fee48285fbeb3135997f2efe6
Fix typo in unused method.

Otherwise I'd've spotted it causing failures.

Change-Id: I5a767b0be1761ffca3f6038484ea37011e0be819
Fix typo in assertion.

Change-Id: Ia0a780b80b95f6175b0f4c6ea4a8ec6369af71ec
Extract useful code to helper.

So that we can easily check editing other users.

Change-Id: Idafa412afe23cc64703bd8670675a0063599aec7
Fix #2208: Make college refresh also update user list.

Previously, the user listing of a college didn't update when it was
refreshed -- it only updated the information about the current list
of users. This change fixes that issue, and ensures that whenever
we try to edit a user that doesn't exist, the edit view is cleared
suitably.

Change-Id: Ice7db1084f192657c535f965f9d94a4bf9f32f01
Add a tests for college refresh after adding/removing users.

This introduces a new user whose username doesn't begin with a number,
since numbers aren't valid first characters for html ids or classes
and would thus cause issues.
We ensure that the user is either added or removed to the list as
expected. In the remove case, check that if editing another user,
the edit session is unaffected, but if editing the removed user,
that the edit session is closed.

Change-Id: I8558f9a72ac8698e7c1b77c9c655fb1bcb25f0bf