add documentation for the convention that _main.c or _test.c files are automatically included in the build.
add documentation for the convention that _main.c or _test.c files are
automatically included in the build.


git-svn-id: 9ecf60ce9baff443e30a0472d3fd222fcb8117cf@1844 7b97033b-253e-4a5c-9b07-e25f9089a9fd

KestrelInstitute/Specware,KestrelInstitute/Specware,KestrelInstitute/Specware,KestrelInstitute/Specware,KestrelInstitute/Specware