added "count" field to DB table to keep track of how many times
we've refreshed.
- show refresh schedule on main courses page
- default for random structure is all units, not 1
svn path=/trunk/boinc/; revision=15846
which added only confusion.
Implement login directly, using cookies.
- All cookie setting/clearing now goes through two functions,
send_cookie() and clear_cookie().
These deal with path and expiry
(e.g. if you want to have different language or forum settings
on two projects on the same server, that now works).
svn path=/trunk/boinc/; revision=14735