[cvs-nhc98] patch applied (hat): Refactor hat-observe:

[Malcolm Wallace]

Tue Feb 26 03:06:24 PST 2002  malcolm
  * Refactor hat-observe:
    * rename 'precision' to 'cutoffdepth'
    * '<RETURN> for more equations' is now a moded dialogue
    * introduce a simple command type and an interpreter to
      translate keystrokes into commands
    * adopt a Hugs-like ':command' syntax
    * state toggles have now become explicit commands :set or :unset
    * the 'show' command is now :info
    * the :help text is updated to show the new command syntax

    M ./src/hattools/HatObserve.hs -255 +218