effectively making the currently selected configuration the only one
active and removing boot configuration selection menu.
This is accomplished by running 'newbtconf revert'.
From PR bin/17808 by myself. Thanks to gendalia and lukem for the help finding
the right keyword.
Approved by lukem.
a little used server daemon which can be controlled with rc.conf in any case.
(xxx: list of files probably should be totally configurable, but that's
another story). from [bin/13061] by matthew green.
