Itv.pm: new swfUrl causes downloads to stop working

On the week of 14 June 2013, the ITV player URL changed to

https://www.itv.com/mediaplayer/releases/13.6.1.3/ITVMediaPlayer.swf?v=13.6.1.3

From the old mercury one, causing rtmpdump swfUrl hash validation to fail and
downloads to stop working.  Fix by refactoring the Itv.pm module to make
updating the swfUrl in a single place work much better and change the URL to
be the new one.

Signed-off-by: James Bottomley <James.Bottomley@hansenpartnership.com>
1 file changed