Bug fixes for Holtman transparent negotiation implementation. Not active

unless compiled with #define HOLTMAN (see comments in the code). Protocol
bugs noticed and patched by Koen Holtman.

Bugs fixed are:
 * implement speculative vs. definite q values [Koen]
 * do not fiddle q values for language or media types [Koen]
 * return choice via an internal_redirect instead of run_sub_req, to
   prevent wrong handler getting onto the response
 * use neg->use_transparent_neg to determine if we are running tcn


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@76925 13f79535-47bb-0310-9956-ffa450edef68