make Data.Graph portable (no change to the interface)
make Data.Graph portable (no change to the interface)

The algorithm now uses STArrays on GHC and IntSets elsewhere.
(Hugs has STArrays, but avoiding them saves a -98, and boxed arrays
aren't fast under Hugs anyway.)

ekmett/containers,iu-parfunc/containers,ekmett/containers,Zigazou/containers,hvr/containers,meiersi/psqueues-old,shockkolate/containers,hvr/containers,shockkolate/containers,hvr/containers,shockkolate/containers,Zigazou/containers,iu-parfunc/containers,ekmett/containers,iu-parfunc/containers,Zigazou/containers