With the normalization of magimail's Makefile,
we can further simplify this logic.
Integrate the WWW logic into GNUmakefile.common.
Remove the custom `Makefile.sunos` files: just
use a conditional in the Makefile.
Signed-off-by: Dan Cross <patchdev@fat-dragon.org>
Delegate most of the logic to a "common" GNUmakefile,
with each system-specific GNUmakefile only setting a
handful of necessary variables.
Signed-off-by: Dan Cross <patchdev@fat-dragon.org>