PostgreSQL supported platform report and a patch.

I am including a set of 4 small patches that enable PostgreSQL 7.3b3 to build
successfully on OpenUnix 8.0. These same patches should also work for UnixWare
7.x. I will confirm that tomorrow (Nov 7, 2002).

Here is an explanation of the patches:

1. An update of the FAQ_SCO file.

2. This patch removes a static declaration of a in-line function in
src/backend/utils/sort/tuplesort.c

3. This patch to src/makefiles/Makefile.unixware, together with the patch to
src/Makefile.global.in allows any addition library search directories (added
with the configure --with-libraries option) to be added to the rpath option
sent to the linker. The use of a different variable to pass the addition
search paths was necessary to avoid a circular reference to LDFLAGS.

4. This patch creates the variable (trpath) used by the patch to
Makefile.unixware. This patch would also be for other platforms that would
have to add the additional library search paths to the rpath linker option.
See Makefile.unixware for an example of how to do this.

After applying these patches, PostgreSQL successfully compiled on OpenUnix 8
and it passed all the regression tests.