added video preview

git-svn-id: https://plugins.svn.wordpress.org/bitcoin-ticker-widget/trunk@851277 b8457f37-d9ea-0310-8a92-e5e31aec5664
added video preview

git-svn-id: https://plugins.svn.wordpress.org/bitcoin-ticker-widget/trunk@851280 b8457f37-d9ea-0310-8a92-e5e31aec5664