Make _node_reference_potential_references_standard return node type

Hi,

I'm working on a different widget-type for node references, where I want to differ the look of selected nodes by their node-type, so it would be really sweet if
the function _node_reference_potential_references_standard could return the node-type. It already selects the type-column from the database, so it's only a question of adding it to the $refereences array.

Attached is a patch that does it.

It would be really sweet if you could add this functionality! IMHO it doesn't impact anything, only adds further extendability.

Thanks!

Regards
Morten