every second (!?) a new thread checks the database for reminder
countdown items that haven't been reminded about yet. when the at time
is reached, the thread sends the reminder and notes that a reminder was
sent
bss/dr.botzo#11
extending countdown items in order to have them also store reminders,
which are the same idea (an event at a time) but these are watched by
the irc bot and sent to the specified destination when the time is
reached
this adds support for configuring this, code in support of it is coming
in later commits
bss/dr.botzo#11
