ochre-lang

Copperbox revision 3156.

I've implemented a simple version of trait flattening (essentially cribbed from the Flattening Traits paper - Nierstrasz, Ducasse and Scharli).

I'll need to put it in the Compiler monad so it can log conflicts etc. and I'll have to add cycle detection for trait definitions, but at the moment it seems to work for my small example.