Unified Make System for Building GraphApp
by Alex

This Makefile system uses a unified Makefile (common.mak)
which contains the rules for building the various source
files in GraphApp. Then there are various platform-specific
Makefiles which set up the variables needed to make
the unified Makefile work.

Alex wrote some instructions which I have included below:

There is just ONE master make file that contains all compilation
rules and files to be compiled.
This makes maintainance and updating a lot easier.
So far, it has been used sucessfully with the following combinations :
1 - Win32 + MSVC
2 - Win32 + gcc
3 - Linux + gcc
4 - TRU64 + cc
For each combination, I have a set of platform specific variables :
compiler options, file extensions and so on. Just ten lines each
(well, more or less) in separate files. Then, at the end of each of
these files, the same master common make file is included.
(There is a template file that can be used to test any other combination.)

Building GraphApp becomes very straightforward (no need to copy
anything anywhere). Just type one of :
1 - 'nmake /f builds\msvc.mak'
2 - 'make -f builds\gnuw32.mak'
3 - 'make -f builds/gnux11.mak'
4 - 'make -f builds/tru64.mak'
There are also a couple of other platform specific set of variables
in the subdir builds, that I have filled after the examples already
in 'src/rules', but I have never tested them.
