Fix PR#1159: Configure always exits with return code 0 -- need a variable

to tell the trap what exitcode to use.

Eliminate the need to use `pwd` which was causing big long ugly -I lines
in the Makefiles.  Instead we build variables INCLUDES_DEPTH0,
INCLUDES_DEPTH1, INCLUDES_DEPTH2 which have the appropriate level of -Is.
Add names to INCLUDES_AUTODEPTH and they'll be -Id to the right level.

Remove the symlinking of os.h and os-inline.c.  Instead $(OSDIR) is added
to INCLUDES_AUTODEPTH.

modules/proxy/Makefile replaced by modules/proxy/Makefile.tmpl, which has
all the right substitutions done on it -- so that, for example, the proxy
gets the right regex.h.

To facilitate the previous, I had to touch a file
modules/proxy/Makefile.libdir...  which just means "the tmpl includes all
the necessary Makefile recipies, just prepend Makefile.config to the
front".  i.e. Configure shouldn't generate all the targets like it does
for modules/standard, and modules/extra.  This is probably something that
we'd want for all AddModules modules/foo/libfoo.a ... but I didn't feel
like groking the awk fooness in Configure.

modules/example/Makefile replaced by (essentially empty)
modules/example/Makefile.tmpl.  So that it has proper substitution done on
it.

Remove some last-built cruft that stuck around after some other patches.

Change rm $(OBJS) to rm *.o to ensure we remove all cruft .o files.

modules/Makefile now has Makefile.config prepended to it, so that, for
example, RANLIB is set properly.

Reviewed by:	Jim Jagielski, Martin Kraemer


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@79347 13f79535-47bb-0310-9956-ffa450edef68