* Add new configuration for multi-domain relay hosts (#922)
* Creates new environment variables (replacing existing AWS_SES variables)
* Optionally allows more advanced setups using config files
* Update relay hosts during change detection (#922)
* Add helper scripts for adding relay hosts and per-domain auth
* Allow the possibility to deliver some mail directly
* adding a domain with no destination will exclude it from the
relayhost_map and so Postfix will attempt to deliver the mail directly
* tests for setup.sh script
* tests for relay host configuration
* these tests cover the code in `start-mailserver.sh` dealing with both
the env vars and the configuration files
* Added dependencies, binary, startup configuration
* Added env variable to dist files/readme
* send summary after each logrotate, added env variable for mail/logrotate interval
* remove mail.log from rsyslogs logrotate
* rotate mail.log when no email is set
* Added documentation for POSTFIX_LOGROTATE_INTERVAL
* Removed interval option, since its not being tested for.
* changed test to force logrotate to rotate fixed logrotate config
* readded setup_environment, made logrotate_setup being called everytime
* changed documentation for new variable names - again
* Did Documentation, added a default recipient, added test for default config.
* layout fix
* changed variable names apposite the documentation
