Finished jobs have to send a status email to the mailing list (#45)

This is for issue #45.
I configured the jobs to send emails, similar as we do on mozmill-ci. Make different reg-ex for the mail subject, and I tested it on staging node, because from local node it can't send emails through mozilla smtp server (smtp.mozilla.org)
the watcher plugin still cannot use variables? I really would like to see that $NOTIFICATION_ADDRESS is used everywhere.