Checking in changes prior to tagging of version 0.03.

Changelog diff is:

diff --git a/Changes b/Changes
index b0486ea..24300f5 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,9 @@
 Revision history for Plack::Middleware::MemoryUsage

+0.03  2013-04-04
+  * Enable to filter by package name
+    (thanks tohae)
+
 0.02  2013-01-17
   * Use B::Size2 instead of B::Size