Making it possible to call collection methods in the ResultSet directly from a Query object

This completes the "fantasy" of a Query as the result itself. This one is quite important to have as setting the results of a `$table->find()` directly to the view would not work correctly if collection methods are called on it from the template or a helper. With this change, users don't have to worry if the query has been executed at all before it is passed to another method.