Checking in changes prior to tagging of version 0.52.

Changelog diff is:

diff --git a/Changes b/Changes
index 944d16c..cbc5f3f 100644
--- a/Changes
+++ b/Changes
@@ -2,6 +2,9 @@ Revision history for Perl extension WWW::YouTube::Download

 {{$NEXT}}

+0.52 2013-05-05T16:18:54Z
+        - Added playlist_id() and video_id() method (kucharskim++)
+
 0.51 2013-05-03T07:49:29Z
         - Support new url (mikolaj++)