Files that used to be called blah.asc are now blah/asc.
Files that used to be called blah.doc are now blah/d.
Files that used to be called blah.txt are now blah/t.
pgp.1 is now pgp/1.
przon26i.asc is now prz26i/asc.

The short extensions are just because most of them were being
truncated, and I thought uniformity a virtue here.

-- GJM
