Best way to apply new suffix rules recursively.

[Chris Cowan]

I have a multiple subdirectory project.  I'm wondering what the best
way is to introduce a new set of suffix rules, so that they are
included in all the Makefiles throughout the hierarchy.

If possible, I would like to edit the suffix rules in one place.  I
realize that I can use include processing.  I'm just wondering if
there is a way I can add the rules to the toplevel Makefile.am or
configure.in and have it recursively inserted in all of the subdir's
Makefiles as they are generated, without making changes to each
subdir's copy of Makefile.am.

Regards,
Chris Cowan