Merge pull request #15 from kucharskim/master

Mainly fix for certain videos, like provided by Vevo
Added commnet
minil build
Checking in changes prior to tagging of version 0.54.

Changelog diff is:

diff --git a/Changes b/Changes
index ca6ed42..0c13f35 100644
--- a/Changes
+++ b/Changes
@@ -2,6 +2,10 @@ Revision history for Perl extension WWW::YouTube::Download

 {{$NEXT}}

+0.54 2013-07-05T18:29:31Z
+        - If unavailable video, croak with an appropriate error message. (kucharskim++)
+        - Support encrypted signature video. (kucharskim++)
+
 0.53 2013-06-05T16:05:56Z
         - Various improvements to youtube-playlists (kucharskim++)