Exposing the pagination specifics in the API

Transforming this:

```ruby
results = api.form("everything").submit(@master_ref)
# results is an array of Document objects
```

into this:

```ruby
documents = api.form("everything").submit(@master_ref)
# documents.results is the array of Document objects
```

in order to be able to also do this: `documents.page`, `documents.total_results_size`, ...