Autoconf-like #defines in distributed header file

[rm]

Hello list/maintainers,

working on the autoconf-ing of mod_guile i
just realized that the guile build process
(via autogen.sh) uses 'atoheader' to produce 
libguile/scmconfig.h.in which is later processed
by configure to generate libguile/scmconfig.h.
I think this use of autoheader to produce a header 
file that gets distributed might create problems in
situations where libguile is used by other autoconf-
enabled software. If suchsoftware uses its own version
of 'config.h' (which is _not_ supposed to get installed)
like in the following example:

| 
| #include "config.h"
| ...
| #include <libguile.h>
| 
| 

... '#define's from the build phase of libguile leak into the
software's build. '#define PACKAGE_VERSION ""' from scmconfig.h
will override the softwares own version of the value and possibly
introduce errant behaviour if the software uses this value for 
its own version testing.

Fix: probably create scmconfig.h.in maually, avoiding the general
'#define's (or moving them to config.h.in or any similar file that
doesn't get installed).


 Ralf Mattes