Mullein

Copperbox revision 561.

The stateful shorthand that I've been using to build note lists (i.e. having a unit note length) stopped seeming useful - I expect Mullein's real utility to be programmatically generating note lists, and the stateful shorthand seemed to complicate things.

I've removed the shorthand from note lists, I'll have to look at removing the rest of it in building phrases and motifs.