[cvs-nhc98] patch applied (hat): Allow for negative big Integers in the hat file format.

[Malcolm Wallace]

Fri May  4 07:35:16 PDT 2001  malcolm
  * Allow for negative big Integers in the hat file format.
    * If the "size" byte is negative, then the whole number is negative.
    * There is no special encoding in the rest of the value - it is
      always a positive number, only the sign bit (in the size) can change.
    * Update hat-connect and hat-stack to print the minus sign.

    M ./src/hattools/utils.c +4
    M ./src/old/runtime/fileformat.c -1 +3