chang the default period_time to 50ms.  On my setup, setting the period_time to 0ms sounds like complete crap.  50ms is the default that xmms has used for years, so lets just stick with that.

git-svn-id: https://svn.musicpd.org/mpd/trunk@4433 09075e82-0dd4-0310-85a5-a0d7c8717e4f