Add other universal course utlities

[kylehg]

This is mostly a placeholder issue for some other registrar utilities that could be bundled as part of this module.

• A Semester object that handles semi-complicated semester logic. (PCR has one internally that's already decently well developed.)
• Course code format normalizations: There are lots of different formats used both by ISC and by students for referring to a course (e.g., "CIS-120-001", "CIS120001", "CIS 120001"). A simple utility function or thin Course/Section class would fix this.