Exposing pagination fields in SearchForm.submit

Transforming this:

```javascript
Api.form('everything').ref(Api.master()).submit(function(err, results) { /* results is an array of Docs */ });
```

into this:

```javascript
Api.form('everything').ref(Api.master()).submit(function(err, documents) { /* documents.results is an array of Docs */ });
```

in order to be able to also do this: `documents.page`, `documents.total_results_size`, ...