Follow playlist updates.
WIP: Collection hacks

TODO

- Collections functions in xmmsclient build upon the protocol
in ipc.xml, so generated code is actually wrong.

- What to do with non-string attributes?

xc.collection_query_infos(
	SmallerEqual("date", "1967",
		Equals("artist", "The Doors", Universe())),
	0, 0, ["album"], [])

works, but

xc.collection_query_infos(
	SmallerEqual("date", 1967,
		Equals("artist", "The Doors", Universe())),
	0, 0, ["album"], [])

fails in the server for some reason.