MX-10 not sending mail when no email address is provided
MX-10 ability to disable sending mail completely (handy for development purposes...)
MX-10 added about column to mail_log to be able to check whether reminders for a particular week have already been sent
MX-10 renamed about to maIl_event
MX-10 dropped mail_type and mail_log_assignment; replacing them with a generic table for simplicity and performance