xmms tag code conversion and more

[Norikatsu Shigemura]

Hello xmms developpers!

	I'm tring to take up a following PR.
	http://www.freebsd.org/cgi/query-pr.cgi?pr=ports/65934

	I think that this should be commited this PR.  Because it cannot
	be only itself, so I must fix many many xmms plugins dependency
	in ports system.  But I think that this is very useful.  And so,
	would you please merge from following URL's feature?

	http://www3.big.or.jp/~sian/linux/products/xmms/index.html.en

	I considered to merge to multimedia/xmms port, too.  But it
	contains very useful features for all world users.