Clean up/rename match-components-of-propn-pair, match-args.

match-components-of-propn-pair was adding mapnode ids to mapnode maps
after creating them.  Now match-args is revised and rewritten as
mapnode-map, and it adds the mapnode id.  This is used now everywhere in
match-components-of-propn-pair to create the mapnode maps.  Also changed
to match-components-of-propn-pair to return conses rather than lazyseqs.
Doesn't matter--all that matters is that a seq be returned--but I
prefered to use cons twice rather than list and then concat.
Revised add-families-wts-to-mat! so doesn't go over each link twice.

Using doseq and clojure.math.combinatorics/combination rather than
for as before to iterate through the pairs of mapnodes in each
propn-pair family of mapnodes.  Haven't test this at all.