Bundle helpers for url_rewrite

Adds the --enable-url-rewrite-helpers configure time option.
see release notes or ./configure help text.

Bundles two 'fake' helpers with exemplar code for shell and C++ coding:

 url_fake_rewrite
	- C++ helper with old non-concurrent protocol.

 url-fake-rewrite.sh
	- shell helper with concurrent and non-concurrent protocols.

Also, some polishing is done to debug code for helpers.

diff --cc configure.in
Simple merge

diff --cc doc/release-notes/release-3.2.sgml
index cfd974717ac32fa61af8d6cd272dac65a5dff297,cfd974717ac32fa61af8d6cd272dac65a5dff297..cf35b4af4cb9e73bd5f6fc6e5b890c31aa8e6c49
--- 1/doc/release-notes/release-3.2.sgml
--- 2/doc/release-notes/release-3.2.sgml
+++ b/doc/release-notes/release-3.2.sgml
@@@ -306,9 -306,9 +306,12 @@@ This section gives an account of those 
  <sect1>New options<label id="newoptions">
  <p>
  <descrip>
--
--      <tag>???alphabetical list within group ordered: enable, disable, with, without) ???</tag>
--      <p> ???explain??
++      <tag>--enable-url-rewrite-helpers</tag>
++      <p>Build helpers for some basic URL-rewrite actions. For use by url_rewrite_program.
++         If omitted or set to =all then all bundled helpers that are able to build will be built.
++         If set to a specific list of helpers then only those helpers will build.
++         Currently one demo helper <em>fake</em> is provided in shell and C++ forms to demonstrate
++         the helper protocol usage and provide exemplar code.
  
  </descrip>
  

diff --cc src/protos.h
Simple merge