Observable polyfill

[streamich]

Now that Observable is part of the standard, what do you'll think about splitting the rxjs library into two pieces: (1) polyfill for Observable standard, which can be loaded in Node.js and browsers that don't implement the standard, yet; (2) the remaining rxjs functionality.

Thoughts?

[dariomannu]

Also, should RxJS have its own one or should it work with/on top of an independent one, perhaps something like the novel observable-polyfill?

If the above commits to remain 100% standards compliant, it would make sense to work on top of that. Perhaps with a few performance tweaks, in case.

However, given that code is currently mimicking the WICG algorithm and description step by step might not be trivial to optimise for size and performance without deviating a bit from the literal mirroring of the WICG description...