Add proof-of-concept hooks for unhandled rejections, plus simple monitor that tracks and logs the current list of unhandled rejections.
Track pending promises and match them up with unhandledRejections in preparation for stitching together disjoint stacks.
Separate monitor prototype into smaller modules with tighter responsibilities: API, aggregation, and simple console reporting.  Remove setInterval in favor of a more event-based approach.
Improve stack filtering by conflating and injecting a marker to represent promise internals.  Capture reason as an error if it's not one originally
Split out formatting and stack filtering
Add comments to deep-chain
Move log message to top level--makes supporting classes even more generic. Remove unused require, reformat bits for readability
Tweak api names, add more examples
Clean up monitor code. Fix observed promise untracking. Add map test