* gnu/tests/audio.scm (%mpd-os): Use the default 'mpd-configuration'.
(run-mpd-test)[test]("mpd listening"): New test.
("mpc connect"): Use 'system*' and 'test-equal'.
* doc/guix.texi: Add documentation.
* gnu/services/audio.scm (<mpd-configuration>): New record type.
(mpd-service-type): New service type.
* gnu/tests/audio.scm: New file.
* gnu/local.mk: Add new files.
Signed-off-by: Christopher Baines <mail@cbaines.net>