Checking in changes prior to tagging of version 3.71.

Changelog diff is:

diff --git a/Changes b/Changes
index 51f4b58..609e751 100644
--- a/Changes
+++ b/Changes
@@ -1,3 +1,11 @@
+3.71 2013-02-12T18:04:33
+
+    [EXPERIMENTAL FEATURE]
+    - Added Amon2::ContextGuard class.
+      (tokuhirom)
+    - Added Amon2::LocalContext class
+      (tokuhirom)
+
 3.70 2013-02-12T09:03:28

     [Web::Request]