Add automatic set of *pprint-width* to terminal width.
Change match-propn-components to put propn-family pairs in seqs, arg pairs in vecs. Also match-propns returns lazy seq of seqs now.

This allows testing for whether you're looking at at the three pairs
from two propns, or the pairs from two arglists, by testing with seq?
and vec?
Modify fmt-pair-map-families and its helpers to handle new rep of pair-map trees, and display more conveniently.