Oembed

I created a widget for oembed, the widget will be loaded from the contentpreview widget when a link of the whitelist is entered. 27 3rd party sources are working like youtube, vimeo, soundcloud,...

Added the library that I used https://github.com/starfishmod/jquery-oembed-all
and added a new function in this library to update a provider. 

I created a pull request for this library https://github.com/starfishmod/jquery-oembed-all/pull/82