Updated code to restrict list of users. Also includes changes to
ensure that a cm_info object is available (required for availability
checks).
There is a tweak to upgradelib to reflect the different fields used.
(Note that upgradelib is not used during upgrade, but only when
converting assignments from the old assignment module.)
This means that the $PAGE->url is properly set for all pages and is required to fix some edge cases with the comments api when
javascript is disabled. It also means logging in after a timeout will work nicely and other Good Things (tm).
sam marshall