mod_reqtimeout: Allow to configure (TLS-)handshake timeouts.

The timeouts apply between the process_connection and pre_read_request hooks.
They are disabled by default for compatibily reasons.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1853906 13f79535-47bb-0310-9956-ffa450edef68