[cvs-nhc98] Improve highlighting in hat-explore:

[Malcolm Wallace]

malcolm: Thu Feb 14 17:37:18 CET 2002

Update of /usr/src/master/nhc/src/hat/tools
In directory hinken:/tmp/cvs-serv29331

Modified Files:
	HatExplore.hs HighlightStyle.hs SExp.hs 
Log Message:
Improve highlighting in hat-explore:
  * have a different style for the current highlight, as opposed to
    previous selections further up the display
  * make the highlighting styles user-configurable
  * try to minimise the amount of screen-repainting required