* mandos (Client.disable): Rename keyword argument "log" to "quiet",
with inverted sense. All callers changed.
(ClientDBus.disable): Rename keyword argument "signal" to "quiet",
with inverted sense. All callers changed.
(main): Disable D-Bus use if bus name is not available on system bus.
(main.cleanup): Bug fix: Only do "remove_from_connection" on clients
when using D-Bus.
* plugin-runner.c (main): Return EX_OSERR if a bad error happened when
trying to open config file.