[m-dev.] Automatic generation of map, foldr, foldl [fwd]

[Lee Naish]

I haven't done member yet but I have just done same_shape_* (an instance of
map) and list_from_* (an instance of foldl - gets the list in the simplest
most efficient way, which happens to be reverse preorder I think), since I
wanted these for my data structure and didn't really want a version of
foldl with 15 odd arguments.

      lee