Favorites and Last Viewed features

This adds a Favorites and Last Viewed section.  Each feature is disabled by default, but has block settings to enable them.  Last Viewed also has a configurable amount of courses to show (a maximum amount, defaults to 5).  Both sections are still sortable as if they were course categories, but the courses inside them cannot be sorted.  Last viewed courses are in order from most recently visited down and Favorites are always alphabetized.