Add new authz/authn API defined in httpd-2.4. It adds new directives
PerlAddAuthzProvider/PerlAddAuthnProvider to register providers and
RequestUtil::register_auth_provider method.

This commit is initial try to port this new API to mod_perl and it definitely
needs a review.



git-svn-id: https://svn.apache.org/repos/asf/perl/modperl/branches/httpd24@1448098 13f79535-47bb-0310-9956-ffa450edef68