Backpressure: Use new "onbufferedamountlow" event instead of setTimeout hack

[feross]

Hooray – the event we wanted was added to the WebRTC data channel spec and implemented by Chrome! See: https://code.google.com/p/chromium/issues/detail?id=496700

Now, let's support it in simple-peer!

Ideally, we can eliminate the hack for Firefox too, but we need to check if they've implemented the new event yet, or not.

[feross]

This is now supported in Firefox too – we should really support it now!

https://bugzilla.mozilla.org/show_bug.cgi?id=1178091

[feross]

cc @mafintosh

[mafintosh]

Wow. I feel like we made an impact here :) We should definitely add that to simple-peer.

[feross]

Yeah! When the activity on the mailing list is super low, I think one email can make a big difference!

[du5t]

Just checking up; do you think this is the cause of my issue with swarmlog? @substack sent me here lol

[feross]

@du5t It's possible. Not sure, though. PR welcome!