Add Stream support

[skerit]

Code needs a little work, but I'd love to know what you'd think about adding a Stream source.

It might be fairly trivial to add your own custom sources, but it would be nice to be able to do:

var player = new JSMpeg.Player(my_stream);

or

var player = new JSMpeg.Player(null, {source: JSMpeg.Source.Stream});
player.source.setStream(my_stream);

This would add support for streams from browserify or socket.io-stream.

There's also a native stream standard in the works for Javascript, it's currently only supported in Chrome but it might be interesting to incorporate that, too?

And by the way: great job on the rewrite. Using a TS makes much more sense and I'm finally rid of annoying artifacts.