Embed bs.to by CodeSpoof

With this addon every stream host on burningseries (bs.to) will be embed in the site instead of some having only their URL shown. Currently this only applies to Vivo, Vupload and SendFox as far as I know. If I missed something, please comment with the host's name and the URL to an episode, where I can find it. Also, SendFox is not yet implemented since I couldn't find a SendFox stream, when I wrote this, so please also comment a bs.to-URL to an episode with a SendFox Stream, so I can implement it.