[cvs-nhc98] patch applied (hat): Improve highlighting in hat-explore:

[Malcolm Wallace]

Thu Feb 14 08:37:18 PST 2002  malcolm
  * 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

    M ./src/hattools/HighlightStyle.hs -2 +4
    M ./src/hattools/SExp.hs -24 +18