express.js example is out of date

[pmanijak]

There are a few places where this file (examples/express.js) is out of date.

Express 4:

• express.createServer() has been deprecated
• passing the status via send() has been deprecated
• convention is to use 'req' and 'res' instead of
  'request' and 'response'

Nano 6:

• error['status-code'] is now error.statusCode

Also there was a syntax error (too many curly braces), and expressjs.org no longer exists / it is expressjs.com.