Merge r1675533 from trunk.

mod_log_config: Add %M format to output request duration in milliseconds.

Committed by: breser
Reviewed by: breser, druggeri, ylavic
Backported by: ylavic


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1678706 13f79535-47bb-0310-9956-ffa450edef68