* mod_proxy*: ProxyBlock fixes; PR 43697 and more.

        trunk patch: http://svn.apache.org/viewvc?rev=1365001&view=rev and
                          http://svn.apache.org/viewvc?rev=1365020&view=rev and
                                            http://svn.apache.org/viewvc?rev=1365029&view=rev
                                                 2.4.x patch: http://people.apache.org/~jorton/ap_proxyblock-24x-v2.diff [avoids major MMN bump]
                                                      +1: jorton, rjung, jim



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1366693 13f79535-47bb-0310-9956-ffa450edef68