Committing pat's rewrite of the stored playlist code. This also adds two

new commands: playlistmove and playlistdelete.

git-svn-id: https://svn.musicpd.org/mpd/trunk@6116 09075e82-0dd4-0310-85a5-a0d7c8717e4f

TODO

@@ -40,12 +40,8 @@
 	*) abstract out state code from playlist.c
 	*) put MPD Version in statefile
 
-*) rewrite saved playlist code
-	*) abstract out saved playlists from playlist.c
-	*) new commands
-		*) replace <playlist> /* replace current playlist
-						with saved playlist and
-						keep playing */
+*) add playlistreplace command (replace current playlist with saved playlist
+                                and keep playing)
 
 *) add command for inserting songs in a specific position