Decreasing need to recompile buildmark.c?

[Justin Erenkrantz]

I'd like to see what we can do to minimize our need to always recompile 
buildmark.c.  Ideally, it should only need to be recompiled if httpd is 
being relinked for some other reason - not every single time make is run.

One possibility might be to do something via the $(PROGRAM_NAME) target in 
build/program.mk - i.e. compile buildmark right before we do the httpd link.

Thoughts?  Any other brilliant strategies come to mind?  -- justin