[Gm2] gm2 builds on Free BSD

[Gaius Mulley]

Hi,

* gm2 now builds on FreeBSD 5.2.1
* removed to_upper and to_lower in p2c
* made gm2/gm2-libs/configure and friends test for `strsignal'
* fixed initialization bug (missing memset)
  in gm2/gm2-compiler/Indexing.mod
* also fixed some portability problems in Make-file.in

I'm sure that many will have seen this in previous emails,
but I guess it might be worth rebuilding on all systems which
have currently been reported as a problem. Basically I think
there is a greater chance that gm2 might build on many BSD
derived systems. Solaris, Mac OS, FreeBSD etc..

I'd certainly be interested to hear reports :-). These changes have
now been applied to the CVS repository.

Many thanks,

Gaius