[Yhc] Data.Map

[Neil Mitchell]

Hi Lane,

> Let's do #1 for now.  All the major yhc specific work is under YHC/, so I
> don't expect a very large diff at the end.

One other thing, if when you do change things like commenting out
typeable, you were to use #ifdef's, that would probably aid the
reintegration part. I don't think the reintegration will be too hard,
since it can be done on a per-file basis - it doesn't need to work on
haskell.org all at once, as long as we don't break it for everyone
else.

Thanks

Neil