Add artist for each track and an artist filter

[relick]

The games determined for inclusion don't really follow a pattern, but it's something like this:

• Any Touhou game or Hifuu album included
• Any game where ZUN composed most tracks included (i.e. shuusou gyoku and kioh gyoku but not banshiryuu)
• Any Touhou related track composed by ZUN added on its own.

To make this a bit more consistent, there's a few tracks that should be included that aren't, such as Independent Simulacrum or Drunkard's Lemuria, but also the ZUN focus is a bit muddied by the large number of non-ZUN compositions/arrangements that come from the fighting games. It would be good to actually attribute each track to the correct artists anyway, and then provide a way to filter down to the artists you actually care about.