"compress" program in Haskell

Most of what's here is from Paul Sanders at BT.

The files lzw.c, Lzw.hs, and Lzw.icl (in Clean) are the same basic
deal, from John van Groningen at Nijmegen.  These are *not* what's run
by default, but I would welcome the insight of anyone who messes with
them.

The MAIL file contains some relevant correspondence.