Rudimentary support for storing the term and week dates
Handle terms starting on days other than a Monday
Add command to look up week dates
Rename Cal to TermDates
Store term dates in database, and reload upon startup
Make term names case insensitive
Capitalise term name in week number
Initial implementation of a cron plugin: supports scheduling of one-off events with a time delta
Add scheduleAt method to cron, to allow scheduling by datetimes
Add better help text for !week and !termdates.set
Allow full term names to be given ('autumn', 'spring', and 'summer') by throwing away all but the first three letters.
Initial implementation of regular events
Everything is running in Twisted's thread now, so no need for locks
Better handling of exceptions in cron callbacks
Improve documentation
Fix starting of regular events (albeit in an ugly way)
Simplify plugin interface to cron: restrict it to just that plugin's events
Remove Cron::scheduleAt
Unify Cron::schedule and Cron::scheduleEvery
Fix Cron::setup to use schedule instead of scheduleAt