A first pass at the chunking filter. This is incredibly simple. As

bucket brigades are sent to this filter, it inserts the chunking header
at the front of the brigade.  When the filter sees an EOS bucket, it
adds the 0 chunking trailer.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86090 13f79535-47bb-0310-9956-ffa450edef68