create the Drafts folder for users so K-9 mail doesn't poll unnecessarily, see #129
increase dovecot imap_idle_notify_interval to 4 minutes

Doesn't seem like 2 minutes is a problem, but 4 minutes seems better. A little less bandwidth, possibly less battery usage (though we don't have evidence that's actually true), and the interval should be shorter than any peer timeouts that might occur due to inactivity

fixes #129
control panel: add aliases to the users list
backup must be full on the first run because incremental backup will fail, fixes #134
tools/mail.py should return a non-zero exit status when invalid command line args are given
backup: automatically take a full backup when the sum of the increments get very large
backup: dont remove old increments because then we lose the backup history right before the last full backup, instead let them disappear along with full backups when a whole chain becomes very old
use php5-fpm rather than our own custom launcher script for PHP+FastCGI
whats_next: check that the TLSA record is correct, fixes #139
Merge branch 'master' into controlpanel