Configure: fixed nginx.so rebuild (broken by r5145).

To avoid further breaks it's now done properly, all the dependencies
are now passed to Makefile.PL.  While here, fixed include list passed to
Makefile.PL to use Makefile variables rather than a list expanded during
configure.


git-svn-id: svn://svn.nginx.org/nginx/trunk@5169 73f98a42-aea0-e011-b76d-00259023448c