[master] ed9954c Document the addition of cache_hit_grace in "Upgrading".

[Geoff Simmons]

commit ed9954c96972a662713de657a5c377023e39b854
Author: Geoff Simmons <geoff at uplex.de>
Date:   Wed Mar 14 22:30:56 2018 +0100

    Document the addition of cache_hit_grace in "Upgrading".

diff --git a/doc/sphinx/whats-new/upgrading-6.0.rst b/doc/sphinx/whats-new/upgrading-6.0.rst
index 60af892..7953fa4 100644
--- a/doc/sphinx/whats-new/upgrading-6.0.rst
+++ b/doc/sphinx/whats-new/upgrading-6.0.rst
@@ -691,6 +691,12 @@ Other changes
     They can be turned on with the ``protocol`` flag of the varnishd
     :ref:`ref_param_debug` parameter (``-p debug=+protocol``).
 
+* ``varnishstat(1)``
+
+  * Added the counter ``cache_hit_grace`` -- how often objects in the
+    cache were hit when their TTL had expired, but they were still
+    in grace.
+
 * ``varnishncsa(1)``
 
   * The ``%h`` formatter (remote host) gets its value from