Switch area-of-study lookup to be based on the "catalog year"

[hawkrives]

According to recent conversations with the registrar, your areas of study are all tied to the same catalog year; you cannot have Asian Studies from 2013-14 and CS from 2015-16, for instance.

As such, we should tweak the top of <StudentSummary/> to allow the student to pick a Catalog Year; we also need to be able to store two values for this… one of the selected year, and one of the, er, potential year, to account for the case where we have some student data that's imported and they want to play with a new year, but don't want to save it permanently.

Catalog Year should default to the value of Matriculation.