Add sort capability.

This sounds useful, and could probably be limited to sorting by the following field types:

1. Webform submission field value (e.g. Last Name, Age, Email etc.)
2. Other fields in webform_submission_data: webform_id, sid, name (field name), delta

Sorting by submission date, updated date etc. can be done by loading the submissions from the query then sorting the results.

Try this. It adds "order by" support for the webform submission field value (point 1 above). Point 2 could probably be done separately if required.

Example:

$query->orderBy('field_name', 'DESC');

"ASC" is used if the direction is omitted.

Try the latest dev.