OBMFULL-6017 Can purge obm-locator on Debian.

As the post-rm script is called first with the 'remove' argument, and secondly
with the 'purge' argument, ensure it does not explode the second time around
because the init script has been removed.
OBMFULL-3634 Adds eventtemplate_notify column.

Makes it possible to store the value of the 'notify user' checkbox.
OBMFULL-3634 Saves the attendees notification in event templates.
OBMFULL-3634 Load attendee notification from template.
OBMFULL-3634 Copy attendee notification when duplicating templates.
OBMFULL-3634 Display attendee checkbox correctly.

Ensures the attendee notification checkbox is correctly displayed (also when
editing the template) and correctly populated.