madman meets musepack

Thanks to Scott Wheeler's tireless work on Taglib, madman (the development version in Arch, really) now has support for Musepack (or "MPC") files. This was half-way to being added once before, but support in Taglib makes this a no-brainer. Seems like tag writing in Taglib is still not 100%, but I assume it'll get there. I hope you're happy. :)

To celebrate this, I also fixed Arch downloads. If you got complaints about 2004 last time you tried to get something from Arch, try again.