Complete the integration of mod_heartbeat, mod_heartmonitor and the

loadable mod_watchdog, started with 771581.

This clears my list of missing modules as of 6 weeks ago, might be
a few new still to clear up.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@771589 13f79535-47bb-0310-9956-ffa450edef68