Well foldl/foldr is so well known that it even is in the wiki article about
folds.
And the main difference between the original and my foldl is not just the
starting parameter but that the starting parameter can have another type then
the elements of the seq. See my example, there the elements in the seq is of
type int but the result is of type string. That was my strongest point about
adding this version of the folds.
