add master_alive_interval options
remove __mine_interval_job, moved to minion.py
enable the minion to detect if the master disconnected using a scheduled job. has to be explicitly enabled by
setting the master_alive_interval in the minions config. the handling of the __master_disconnect event is still
POC. not yet sure what to do in it and how to make it as flexible as possible.
Merge pull request #13354 from felskrone/minion_alert_disconnect

Minion alert disconnect