per-node default values for subject/message (patch)

Hi, I would like (and have implemented) the following feature :

Feature description

Be able to set, on a per-node basis, default subject and message filled in when displaying the contact form. This would be very usefull to automatically include context about the email.

Suggestion

A nice way to do this would be to select fields on the content type to act as default subject/message. This would be set when configuring the email field, and all the fields of the current content type would be available

Implementation

The attached patch (against 6.x-1.0) implements this.