Fixes several tests that were previously failing

See ticket #795. This fixes the following tests:
* test_user_attrs Django integration
* testUserInfoPage Other
* testClasses Dashboard (pre-Ajax)
* testStudentStats Dashboard (pre-Ajax)
* testTeacherStats Dashboard (pre-Ajax)
* test_adding_coteachers Other
* test_grade_range_popup Other
* testEditor Theme editor
* testSelector Theme editor