[project @ 2000-03-10 17:30:36 by lewie]

First stab at reviving TREX - just fixing some header wibbles.  Also one small
fix to get implicit parameters working (`textOf' needed to be taught that
IPCELLs are also OK).  Moved #defines for TREX, IPARAM, etc, into options.h
(in their previous location at the end of prelude.h, they were being defined
too late).