Replace {...} with (sorted-map ...) in match-components-of-propn-pair and match-args.

I believe this will guarantee that (vals the-map) will always return the
LOT items that in the same order :alog1, :alog2.  This will allow
add-mapnode-id-to-pair-map to construct the same mapnode id for a given
pair of LOT items each time.  See long comment about this before
pair-to-map-id-pair.