Replace ap_get_data_from_filter and ap_save_data_to_filter with

ap_save_brigade.  This function does not try to save the actual brigade to
a specific location.  If just traverses the brigade, calls setaside if
it is available and concatenates it with a previously setaside brigade.

The resulting brigade is returned to the caller for them to save it to
the appropriate location.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86370 13f79535-47bb-0310-9956-ffa450edef68