Conclusions:
1) an extra bunch of files is a on-issue for most users -- we just
need something that works.
2) the exe launcher is a bit fragile and hard to maintain (and even
harder to debug) -- but there are smart people working on this.
3) I'd rather not have to mess with PATHEXT, and I particularly don't
want to have to tell my students to do it -- environment variables are
a pain, and somehow PATHEXT has been fragile for me (and I don't use
Cygwin)
I cant help thinking a more elegant solution exists, but maybe not.