Feature Request: Add contextual data

[jjwilliams]

Sometimes just re-populating a form with saved values does not quite give the desired behavior I need. If we could specify some "container" type key. Example usage:

Users can perform "investigations", which they fill out some form fields and might query several times. I would like to be able to re-populate the investigation when the form is re-opened PER INVESTIGATION. The ability to specify some key or id when initializing would be great.

Love this plugin! Good job!