Better handling of hostname and email address recommendation.
put a sterner warning in nginx local.conf about not modifying it
re-do allow apt to perform security updates on its own

Move this into system.sh rather than anagement.sh.

This reverts commit eab28c97ff4ff04b452d07dd2f7af882f76f0d33.
Merge branch 'box-in-a-name' of github.com:hjjg/mailinabox