Generating docs

[Simon Marlow]

> BTW, why did you separate Haddock from GHC? I love these vicious
> circles: to build GHC with docs you need Haddock, to build Haddock
> you need GHC ...

You can either use an installed Haddock, or use Haddock from the same
tree (./configure --enable-src-tree-haddock).

It's not really a cyclic dependency: Haddock isn't required to build GHC
itself, so you can build GHC, use it to build Haddock, and then build
GHC's docs.

Cheers,
	Simon