Support x_authoirty.
Checking in changes prior to tagging of version v0.6.4.

Changelog diff is:

diff --git a/Changes b/Changes
index 4b22a11..86eec11 100644
--- a/Changes
+++ b/Changes
@@ -2,6 +2,11 @@ Revision history for Perl extension Minilla

 {{$NEXT}}

+v0.6.4 2013-08-21T08:06:10Z
+
+    - Addex x_authority support
+      (tokuhirom)
+
 v0.6.3 2013-08-20T04:27:22Z

     - version::is_strict is too strict for me. Use version::is_lax instead.