Exp: Async logging

[RobinTail]

This should be a major performance boost for the BuiltinLogger https://expressjs.com/en/advanced/best-practice-performance.html#do-logging-correctly

     name             hz     min     max    mean     p75     p99    p995    p999     rme  samples
   · sync     248,537.46  0.0034  1.1198  0.0040  0.0037  0.0062  0.0078  0.0301  ±1.66%   124269
   · async  6,109,895.93  0.0001  1.0178  0.0002  0.0001  0.0020  0.0021  0.0026  ±0.83%  3055099   fastest

Problems:

• maintaining queue ✅
  • setImmediate() seems to be doing it good enough, but:
• purging the queue on termination ✅
  • using a proprietary stack and use setImmediate() only for printing from it
• collaboration with a graceful shutdown ✅
  • modified installTerminationListener()
• child loggers ✅
  • introducing a registry and the public dispose() method

[coveralls-official[bot]]

coverage: 99.883% (-0.1%) from 100.0% when pulling 775b882d921d4851d82688a94f19b0f8b4a26228 on async-logger2 into 40822e65461e1bd429ba60bf2f1892e32dfd3c27 on master.

[RobinTail]

this implementation does not make a dramatic difference, because the same thread is used for printing the same about of bytes to the sync stream of stdout. Instead, should try dedicated worker thread in another PR