Fixes a threading related independent study instructor bug.
2.2.3
term.is_past method checks the LastFinalExamDay if GradeSubmissionDeadline is null
2.2.2
Handle the case GradeSubmissionDeadline being null. [MUWM-4550](https://jira.cac.washington.edu/browse/MUWM-4550) - TypeError: '>' not supported between instances of 'datetime.datetime' and 'NoneType'"
2.2.1
changed datetime to date on the dates in Term model.
2.2
Changed uw_sws.registration get_schedule_by_regid_and_term to always use verbose. Merge UnfinishedPceCourse into Registration model. Add date/str helpers for converting model dates