[cvs-nhc98] patch applied (hat): Display AtomAbstract values e.g. IO as {IO} instead of _IO_.

[Malcolm Wallace]

Fri Jun 14 03:33:54 PDT 2002  malcolm
  * Display AtomAbstract values e.g. IO as {IO} instead of _IO_.
  Also, fix a display problem with cyclic lists where the terminating ]
  was missing.

    M ./src/hattools/SExp.hs -3 +7
    M ./src/hattools/artutils.c -1 +1