Moving Request and Response into separate modules

[wesleytodd]

Started with some conversation here: pillarjs/router#14 (comment)

Express, Sails and Nighthawk are all doing something similar, creating instances of Request and Response to pass to the router. Currently Express extends directly from http.IncomingResponse which doesn't work for the context of WS requests or browser routing.

The discussion I would like to have here is "How can we create stand-alone modules that can be used for all three use cases?".

cc: @mikermcneil @felixfbecker

[wesleytodd]

Relevant code

Express:
https://github.com/strongloop/express/blob/5.0/lib/request.js
https://github.com/strongloop/express/blob/5.0/lib/response.js
https://github.com/strongloop/express/blob/5.0/lib/application.js#L159-L164

Sails:
https://github.com/balderdashy/sails/blob/master/lib/router/index.js#L168
https://github.com/balderdashy/sails/blob/master/lib/router/req.js
https://github.com/balderdashy/sails/blob/master/lib/app/request.js#L138

Nighthawk:
https://github.com/wesleytodd/nighthawk/blob/master/lib/request.js
https://github.com/wesleytodd/nighthawk/blob/master/lib/response.js
https://github.com/wesleytodd/nighthawk/blob/master/lib/router.js#L187-L198