Support IPv6-sized client strings in mod_status and mod_echo

trunk: http://svn.apache.org/r1837225
       http://svn.apache.org/r1837366
2.4.x patch: http://home.apache.org/~jim/patches/client64v2.patch
+1: jim, icing (by inspection), minfrin


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1841259 13f79535-47bb-0310-9956-ffa450edef68