Add term info to courses on home page

[s-edwards]

Currently, the list of course offerings on the home page does not provide term information. For students, this is probably fine, but for instructors this information should be added.

Based off the list off the courses/ page, The list of offerings on the home page should be split into separate groups, one per term, listed in reverse-chronological order. Use an

to introduce each term, with an

for each course, and a table listing the section(s). The title on the home page should probably be changed from "Your current courses" to simply "Your courses", since it lists all courses associated with the user, not just those in the current term.