Checking in changes prior to tagging of version 0.03.

Changelog diff is:

diff --git Changes Changes
index fd18cb5..022512e 100644
--- Changes
+++ Changes
@@ -2,6 +2,15 @@ Revision history for Perl extension PSON

 {{$NEXT}}

+0.03 2014-04-02T12:01:05Z
+
+    - Support undefined value
+      (Reported by sharl++)
+      https://github.com/tokuhirom/PSON/issues/3
+    - Implemented 'encode_pson' method.
+      (Reported by syohex++)
+      https://github.com/tokuhirom/PSON/issues/2
+
 0.02 2014-04-02T00:04:00Z

     - Documentation update