mpd-git has single command, which provides functionality
of both "repeat one" and "stop after current track" modes.
repeat one = single && repeat
stop after current track = single && !repeat
it should have sent commandlist begin and end commands from the beginning,
having separated functions just to handle queueing commands was plainly ugly.
If a host name starts with a slash, it is assumed to be a unix domain
socket path. The port is ignored. This code is disabled on WIN32,
until someone tests it.
