Adding FGL to the hierarchical libraries

[Ross Paterson]

On Mon, Jan 12, 2004 at 12:57:53PM -0800, Martin Erwig wrote:
> Abe Egnor and Isaac Jones at Aetion Technologies have refactored the 
> modules of the FGL
> (http://eecs.oregonstate.edu/~erwig/fgl/haskell/) into the new 
> hierarchical name space.

A minor nit: Data.Graph.Inductive.Basic should import Data.Tree instead
of Data.Graph.Inductive.Tree