remove artists


Not hearing back one way or the other, I checked in the remove artist stuff.

It is a pretty minor patch. It is cheap (a lambda and an attribute per
artist), but unfortunately not free for those who don' need it :frowning:

I can turn the lambdas into methods pretty easily if the python experts
say the savings will be significant.

I'll submit an example this weekend which uses it. I've got a pretty
extensive application now which uses it, but I need something smaller
for that purpose.

  - Paul