[master] 6ed1b68 Make the gzip docs a bit clearer

[Per Buer]

commit 6ed1b68bb3c8f127d8df7b7377d80579af04adba
Author: Per Buer <perbu at varnish-software.com>
Date:   Mon May 6 16:16:20 2013 +0200

    Make the gzip docs a bit clearer

diff --git a/doc/sphinx/reference/vcl.rst b/doc/sphinx/reference/vcl.rst
index b5f5dec..01a52ad 100644
--- a/doc/sphinx/reference/vcl.rst
+++ b/doc/sphinx/reference/vcl.rst
@@ -716,8 +716,10 @@ beresp.do_esi
   false. Set it to true to parse the object for ESI directives. Will
   only be honored if req.esi is true.
 
-beresp.do_gzip
-  Boolean. Gzip the object before storing it. Defaults to false.
+beresp.do_gzip 
+  Boolean. Gzip the object before storing it. Defaults to false. When
+  http_gzip_support is on Varnish will request already compressed
+  content from the backend and as such compression in Varnish is not needed.
 
 beresp.do_gunzip
   Boolean. Unzip the object before storing it in the cache.  Defaults