Sent Message is Malformed

Issue Summary

The message that SignIt sends to a target (when using SignIt in message sending mode) is malformed. It does not include any of the node fields in the body of the message. It includes a signature for the user that includes a link to the user's drupal contact form. The message also does not include a subject line.

The message sent by signit it should:
include a subject line
Not include a link to the user's contact form

Additionally it would be good to allow the user who creates the signit node to specify ia required message body that can use tokens to include fields from the node.