Support multiple records in response

Also makes the example work with the default demo database. Adds a constructor function for classes, so now this is valid:

```js
db.class.get('OUser')
.then(function (OUser) {
  return OUser.list();
})
.then(function (users) {
  console.log('First 20 users in the DB:', users);
});
```

Also removes the last of the legacy code, we weren't using it anyway.