The NixOS service module loads those modules by default. So we need to build
them here as well.
I'm not really sure why these modules are included by default, because (except
from maybe CGI) they obviously are only usable in very rare cases. Am I wrong?
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
The reason because the configure script is unnable to find libxml2 is because it
is searching for a header file in `libxml/*.h`. Obviously this cases an error,
because it's actually in `${libxml2}/include/libxml2/libxml/*.h`, so let's add
the parent directory to --with-libxml2 and remove the comment from buildInputs.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
