made status.master to switch between __master_disconnected and __master_connected events
to handle that differently in the minions main loop
move the evaluation of what master to connect to from __init__(), to its own method eval_master()

That makes it callable from the minions main event-loop and with that, enables the minion to jump to
the next master on the fly.

Also add handling for __master_connected event to enable the minion to switch between connected and
disconnected mode.
cleanup pylint errors
cleanup pylint errors
Merge pull request #13472 from felskrone/improve_master_alive

Improve handling of __master_alive scheduled job