[kronolith] separate reminder address

[Mark]

It would be extremely useful to have a setting for an email address
different from your normal horde user email address for sending
kronolith reminders to.  In other words, I want to get reminders on my
mobile device, but I don't want all horde messages to go there.

This could also be a horde feature since more than kronolith does reminders.

-- 
Mark
"Blessed is he who finds happiness in his own foolishness, for he will
always be happy."