This shaves off just over a MB off of the installation using gzip -9.
While I was at it, I put in the compression of etc/refcards/*.ps, which
covers part of a TODO.

I wanted to compress etc/refcards/*.tex as well, but I noticed that it
would affect the Makefile that is also installed. It appears to be the
only Makefile that's installed; if there's little or no reason for it,
would it be okay to remove it during installation and compress the *.tex
files as well?