Allow extraction of content url in opengraph video meta tag - og:video
Make meta tag content url extraction rules more generate so as to apply to all meta tags 'content' attributes, not just specific og:video.
Ensure Jerico extractor html doesn't call new metadata test method.
Remove unused variable.
Merge pull request #100 from vonrosen/ari-4061

Allow discovery of urls in content attribute of meta tags.