ochre-lang

Copperbox revision 3175.

More preliminary work before I implement inlining for super-calls.

I've had to take modules a bit more seriously. I was going to leave them until after I'd implemented super inlining, but the simple scheme I had where the intermediate layer only considered instruments demanded by the orchestra spec isn't going to work. Because the super calls of an instrument might resolve to an instrument not in the orchestra spec all instruments in a module need translating upto super-inlining.