Change to config.pl processing in the msvc build environment

I'd like to apply the attached patch to the msvc build environment,
which changes how config.pl is handled. (For the unenlightened, this
is the replacement stuff we have for autoconf)

Today, there is one config.pl. We ship it with a couple of defaults
(which points to a very old installation of mine, really, and probably
shouldn't have included those paths in the first place), and you are
supposed to edit this config.pl file in-place to change which 3rd
party libs etc you have.

This is pretty convenient for end-users building from source. Of which
we don't have many. And it's annoying for doing any development work
on it, because it shows up in your "git diff" or whatever, and you
can't ignore the file or you won't get new updates out.

I therefor propose that we rename this file to "config.pl.default",
and change the scripts to first load config.pl.default, and then load
config.pl if it exists. config.pl then lives completely outside the
source tree (should be in .cvsignore) and won't show up in any diffs
or anything.

It changes the format of the config.pl file (not the default one), so
that the user can now specify just one or two options, and doesn't hav
eto respecify all. So now you can have just:
$config->{zlib}='c:\zlib';

(or similar).

*If* you put in th place the old config.pl file, it will override
whatever is in the default file. Thus, I don't believe this would have
any effect on the buildfarm or the oneclick-installer build
environments.

Comments? Objectsions? Holes in the reasoning? :-)

(patch excludes the rename of config.pl to config.pl.default, for readability)

--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/