#15 Send email notifications when activity is updated

[Mike King]

There is an option to send email notification to the attendees when a
new appointment is setup and this functionality works. But the problem
is that when I make a modification to the meeting (e.g. change the time)
or delete the meeting, there is no email notification sent out.

I think it will be very confusing if meetings are changed or deleted and
no email notification is sent out.