Find the current song's URL and pass it on when possible

schemata/config-v1.json

@@ -24,6 +24,12 @@
 					"title": "Host",
 					"type": "string"
 				},
+				"music_directory": {
+					"description": "Your music directory, just as it's set up in your mpd.conf. mpd-now-playable uses this setting to figure out an absolute file:// URL for the current song, which MPNowPlayingInfoCenter will use to display cool stuff like audio waveforms. It'll still work fine without setting this, though.",
+					"format": "directory-path",
+					"title": "Music Directory",
+					"type": "string"
+				},
 				"password": {
 					"description": "The password required to connect to your MPD instance, if you need one.",
 					"format": "password",

schemata/song-v1.json

@@ -194,6 +194,12 @@
 			"description": "The track number the song has on its album. This is usually one-based, but it's just an arbitrary audio tag so a particular album might start at zero or do something weird with it.",
 			"title": "Track",
 			"type": "integer"
+		},
+		"url": {
+			"description": "An absolute URL referring to the current song, if available. If the song's a local file and its absolute path can be determined (mpd-now-playable has been configured with your music directory), then this field will contain a file:// URL. If the song's remote, then MPD itself returns an absolute URL in the first place.",
+			"format": "uri",
+			"title": "Url",
+			"type": "string"
 		}
 	},
 	"required": [