protect global private variable from being over written by loading definition file
cleaning
allow change some settings via env variables; load definition file during 'on' action to determine gui/headless mode
move default settings to the function so that every 'action' which require settings must load definition file, otherwise unbound variable error should occur
cleaning
add comments to load settings functions
added shutdown time monitoring for the acpipowerbutton
try fix ssh port setup if ssh_host_port or ssh_guest_port changed