Proposal: Add concatMapM function (#2042)

[Neil Mitchell]

Hi

>    1. In favor:
>       - Twan van Laarhoven
>       - Isaac Dupree
>       - Don Stewart
>       - Neil Mitchell
>
>    3. Opposed to any additions to the base library:
>       - Bulat Ziganshin

I don't think 4 people is quite enough to overrule one persons
objections, so I'd suggest that anyone reading this thread who does
want this to go in (as it stands, without generalisation) should shout
up now. I'd guess another couple of me-too's is enough to have a
consensus.

To add one more me-too, Matthew Naylor
(http://www-users.cs.york.ac.uk/~mfn/) says:

> (+1) Me too.

Thanks

Neil