geom part list no longer lists empty disks, compensate where needed.Also, while I'm here, fixup copyright.
Change this line slightly, for some reason it is making my editor crash with the old line.
Change copyright statement to reflect reality
Drop a note on the page about how to repair a failed mirror.
Bring in proper gmirror support for the GUI and notifications.Made a general gmirror library to perform various gmirror tasks and get information, using some of the former widget logic to start. Updated widget to use this new code.Added a Diag > GEOM Mirrors page that displays information about existing mirrors and perform various management tasks. Current actions include rebuilding a drive, forgetting disconnected mirror drives, insert/remove, deactivate/activate, clearing medatada. It's now possible to use the GUI to rebuild a failed mirror by performing a forget, then insert action to replace a missing/dead drive....