Add FoldL.foldM based benchmark

FoldL.foldM is comparable to the fastest loops in the current benchmark.  It however lets you deal with your loops at a high level(ex. Applicative instance, Functor instance).  See the following post, by  Gabriel Gonzalez, for an example:
http://www.haskellforall.com/2013/08/foldl-100-composable-streaming-and.html

It looks like the only reason for it to be slower for the `Word32` version is because of the naive implementation of `enumFromTo` for `Word32`.  I have some additional links in the the mailing list post about it:
https://groups.google.com/d/msg/haskell-cafe/xztdekhf0f8/sWqcrBiKwyMJ


Criterion report for the benchmark on my laptop:
http://htmlpreview.github.io/?https://github.com/Davorak/loop/blob/master/results/bench.html