Experiment with fast-path for fulfilled then() w/no handler
Fully externalize unhandled rejection tracking, even long stack traces. Remove console rendezvous entirely in favor of Promise decoration

Only unhandled rejections that are really observed (ie have a handler)

Tighten context push/pop when calling handlers

Provide backcompat when/monitor/console that monitors when.Promise, and also new when/monitor which can be used to monitor any Promise type created with when/lib/makePromise, including es6-shim/Promise
Disable unhandled rejection reports in benchmarks
Update unhandled rejection API names after discussion with @unscriptable