Checking in changes prior to tagging of version 0.28.

Changelog diff is:

diff --git a/Changes b/Changes
index 2ea00bf..e59bf97 100644
--- a/Changes
+++ b/Changes
@@ -2,6 +2,10 @@ Revision history for Perl module Ukigumo::Client

 {{$NEXT}}

+0.28 2014-04-05T05:49:54Z
+
+    - Add the documentation for elapsed time
+
 0.27 2014-04-03T08:21:51Z

     - Measure the elapsed time (moznion)