Added a method on Gordon's Stream class to retrieve remaining buffer data

[tbrebant]

Added a method on Gordon's Stream class to retrieve remaining buffer data.

Ping @bchevalier @dyoxyne @cstoquer @cainmartin.

[bchevalier]

you added a method that is not used?

[tbrebant]

Yes, just because it's beautiful😄 !

Joke apart, we are using it in in a tool using JEFF.
Gordon could (should?) be an independent component, no?

[bchevalier]

I think it makes sense.
And how is it included? submodule or npm package with npm releases?

[tbrebant]

Now we just require it.
But at long term we should npm package it, yes.