[Yhc] Bytecode API library

[Neil Mitchell]

Yay!

> http://www.eecs.tufts.edu/~rdocki01/yhc-bytecode.html

I haven't downloaded it yet (I'll get to it in a few days :) ), but it
looks pretty much exactly like what I was aiming for, which is very
nice to see!

There is only one really small and minor thing - we have decided to
use the namespace Yhc instead of YHC, since the compiler is
"officially" called Yhc.

It would be nice if we could put this in the main Yhc, if thats ok by
you. I'm not sure if we can give you commit access, but I'll look into
it, and otherwise we can figure out a remote darcs repo and then pull
from it as required. And also it would be nice for the back end of the
compiler to use this as well.

The only remaining this is the license, since none of the original nhc
code made it to this side of the compiler, the only people with
copyright on this stuff (or anything related to it) are you, me and
Tom. Me and Tom both think that maybe LGPL would be more appropriate
for this library, on the basis that then people can use the library
from both a GPL program and a BSD program, and it seems that BSD is
the prefered license for Haskell stuff, so it makes us more
compatible.

Thanks for this great work!

Neil