Few bug fixes, new oembed provider, vine, coveritlive

Added Vine oembed provider. 
takes the following urls and embed as a postcard
http://vine.co/v/bJqWrOHjMmU
http://vine.co/v/bJqWrOHjMmU/embed/simple
http://vine.co/v/bJqWrOHjMmU/embed/postcard
https://vine.co/v/bJqWrOHjMmU/embed/postcard
http://www.vine.co/v/bJqWrOHjMmU
http://www.vine.co/v/bJqWrOHjMmU/embed/simple
http://www.vine.co/v/bJqWrOHjMmU/embed/postcard
https://www.vine.co/v/bJqWrOHjMmU/embed/postcard

fixed a few typos in the oembedprovider, where the nocache parameter is in the wrong object

added coveritlive as a oembedprovider, and embeds it as an iframe