There should be a way to query the supported fields

[ksnabb]

The @supportedFields as described in opensocial specifications should be implemented for the feature properties.

This means that a list of the keys used should be returned. Also the type of the field should be returned.. this can be implemented in a way that it works as is. E.g. 'age' key can be either 'eight' or 8, string or number.

[ksnabb]

I will make a bigger change in version 2.0.x now and after that hopefully only maintain that one so I move this issue to 2.0.x milestone for easier and cheaper maintenance..