[cvs-nhc98] Turn list sugaring back on by default, but ensure that no

malcolm: Tue Jun 18 16:55:58 CEST 2002 Update of /usr/src/master/nhc/src/hat/tools In directory hinken:/tmp/cvs-serv25169 Modified Files: HatTrail.hs HatObserve.hs SExp.hs Log Message: Turn list sugaring back on by default, but ensure that no ambiguous list sugaring is generated, by testing whether the ultimate tail of a list is Hidden, Unevaluated, or Interrupted. A cutoff tail is represented with an additional `...' to remind the user that there are more elements of the list.