Get translation of request bodies working.

This code is pretty ugly, but I need to checkpoint (and this stuff
actually works).

The direction: Get xlate_brigade() working for output too, then
kill the analogous code in xlate_out_filter().  At that point, the
same translation code works for input and output.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86685 13f79535-47bb-0310-9956-ffa450edef68