Add support for request-received middleware

[niftylettuce]

The request-received middleware at https://github.com/cabinjs/request-received exposes a Symbol.for property, which this package could conditionally consume if interested (as opposed to just generating a new Date().

e.g.

sails-hook-responsetime/lib/beforeAll.js

Line 15 in d7f2103

req._timeStart = process.hrtime();

would change from process.hrtime() to req[Symbol.for('request-received.startAt')] ? req[Symbol.for('request-received.startAt')] : process.hrtime()

[luislobo]

@niftylettuce
That is an interesting suggestion. I'll check it out. Are you still interested in this?