PR for queued operations with promises (#314) has been merged

We reached some consensus (mostly between Me, Jan-Ivar, and Martin) on how
to update the how the queued operations (the ones that can only be run one
at a time: setLocalDescription, setRemoteDescription, createOffer,
createAnswer, and addIceCandidate) to incorporate promises (such that they
can return a promise and it's clear when that promise will be
fulfilled/rejected) in PR #314 (https://github.com/w3c/webrtc-pc/pull/314).


The PR has been merged.  Now that those immersed in the gory details of
Promises have reached consensus, and the change is merged, is everyone else
OK with the result?