Trying to fix an accidental reversion of popco.lisp and acme.lisp.  It
appears that on June 7 2013, I did a commit (with comment "trivial I
think") that committed old versions of acme.lisp and popco.lisp
(b40dc073d57691bebad0cb37daa6783521ab8d52).  I think that I was actually
suprised that there was something to commit--that's why I said "trivial
I think".  My guess is that these were versions from summer 2012, since
I had been comparing the functioning of the current system with what it
had been doing back then.  Anyway, I'm not really sure what happened.  I
hope there was nothing else messed up. But if you look at the changed
files in github, these are the ones with big changes.  In this commit, I
first went and got the versions of popco.lisp and acme.lisp as they had
been at the time previous commit
(9497ef0fab45ae201a92da24f1629c950ae4b5c5), and copied them over the bad
versions.  That's what's in this current commit.