Data.* collections maintenance

[Christian Maeder]

Jean-Philippe Bernardy wrote:
> As some demand seem to exist for the job, I volunteer to take
> over/resume maintenance of Data.Map and friends. In the hope that will
> alleviate the heavy load on the compiler maintainers :)

Thank you!

> Pending issues include :
>   - Better integration of Map and Set (proposed by John Meacham)
>   - More performance tests and QuickCheck properties (Christian Maeder)

With respect to biasing I'ld like the following property between Sets 
and Maps.

data Pair a b = a := b

instance Eq/Ord a => Eq/Ord (Pair a b) where
    (a1 := _) <= (a2 := _) = a1 <= a2

and then let "Set (Pair a b)" correspond to "Map a b" for insert, union, 
intersection, etc.

Christian