Accept also beginning of option names now.
Non-active domains with records in arp cache are no longer reported as online.
Forgotten documentation of select_option.
Extend select_option functionality by adding sorting keys for options.
Cosmetic changes.
Various fixes around sorting keys.
Actions are now prioritized and chaning CD/DVD media is now allowed for non-active domains.
Pylint polish.
Removed forgotten debug print.
Fixed changing CD/DVD image for inactive domains.