buildconf: check in APR[-util] m4 macros

Suggestion by wrowe. These files haven't changed in years; since we need
them anyway, check them in directly. buildconf will still copy over the
latest versions during setup, and SVN will tell us if there are any
changes (once I remove the svnignore).

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/trunk-buildconf-noapr@1795928 13f79535-47bb-0310-9956-ffa450edef68