Re-apply the patch from yesterday that makes ap_http_filter use

apr_brigade_partition.  In order to do this cleanly, I had to make
some changes to the apr_brigade_partition API, so this also adds fixes
all of the calls to that function throughout the server.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@90029 13f79535-47bb-0310-9956-ffa450edef68