Implement route() function

Implement a route function to make something like this (new in Express 4.0) possible:

```
app.route('/myroute')
.all(function(req) {
  // runs for all HTTP verbs first
  // think of it as route specific middleware!
})
.get(function(req) {
  return response.json({});
})
.post(function(req) {
  // some code
});
```
