[PATCH] deny_info 3xx code support

Small improvement on the earlier patch.

This adds:

  * automatic selection of 307 response status for non-GET/HEAD HTTP/1.1
requests.
  * support for custom 3xx codes (only 300..399 allowed) to be
configured on the deny_info URL.
  For example deny_info 303:http://example.com/ POST

While retaining the 302 status for all HTTP/1.0 clients in case they do
not support the HTTP/1.1 status.

I've omitted automatic selection of 303 status, since it is slightly
unclear whether it applies to *all* PUT/POST. Easily added at a later
stage anyways.

Testing in production shows that Firefox supports 307 redirection. The
other popular browsers treat it like 302 still.

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE9 or 3.1.9
   Beta testers wanted for 3.2.0.3