Update route.js to support "put" more than 2 levels deep

Modified routes.js to support deeper "levels" 
was having trouble with the code in router.put binding to an $id more than 2 levels deep

```javascript 

while (o && pos.length - 1) {
  o = o[pos.shift()]
}

```

Example:
Using the example from the readme, posting to

```
http://localhost:3000/rest/blogpost/$id/comments/ 
```

will work fine, however if you add another level like

```
http://localhost:3000/rest/blogpost/$id/comments/$id/notes/
```

then an error would occur.

I modified the code to assume that any additional layers would follow a path of

```
/level1/$id/level2/$id/level3/...etc
```