Patch for case of max operands > 127

[Ben Elliston]

   This patch makes a check for MAX_OPERANDS and sets the type of the
   syntax string to be either unsigned char (normal case) or unsigned
   short when appropriate. The patch also makes minor modifications to
   code that accesses the syntax string to ensure it does not make
   assumptions about the type.  Included are ChangeLog entries.

This looks okay to me, if you've tested it on your port where MAX_OPERANDS
exceeds 127.

Ben