Support for fetching/changing usernames, for convert_usernames.pl
This should never have been a .pm!
Stupid mistake fixes.
Support for fetching/updating usernames.
Coverage of get_usernames()/set_username() extended.
Support code for doing SoCS <=> UoM username transformation.
Support for Moodle assignment and student lookup.
Actually do username updating.
Doc updates.
Replacement for the ARCADE query script.