[common] Add common preinstall and postinstall scripts for debian-based images
[ubuntu-icinga2:trusty] Use the common/debian preinstall and postinstall scripts
[phusion-icinga2:trusty] Undefine the /etc/icinga2 volume
[phusion-icinga2:latest] Undefine the /etc/icinga2 volume
[phusion-icinga2:trusty] Undefine the HOME environmental variable
[phusion-icinga2:latest] Undefine the HOME environmental variable
[phusion-icinga2:trusty] Rename icinga2 directory (to setup)
[phusion-icinga2:*] Use the common/debian preinstall and postinstall scripts
[*-mysql-base:*] Use the common/debian preinstall and postinstall scripts
[ubuntu-mysql:trusty] Rename icinga2 directory (to setup)
[phusion-mysql:trusty] Rename service directory (to setup)
[ubuntu-mysql:trusty] Move directory cleanup out of the setup
[ubuntu-icinga2:*] Move setup cleanup to the Dockerfile
[ubuntu-mysql:*] Update installer to use common debian package scripts
[debian-postfix:wheezy] New Image
[ubuntu-postfix:trusty] New Image
[phusion-postfix:trusty] New Image
[phusion-postfix:latest] New Image
[docs] Add postfix image documentation