Allow editing subject when forwarding messages

When using FSEditor, if you forward the message, you're not given an option to edit the subject. There are occasions you'd want to do this, such as trying to resend a bounced message to a different address, the original is often included in the reply, so you can change the email and remove the bounce text but I'd want to remove the "Re:" from the subject line.

I'm using DDMsgReader so I don't know if this is a Nightfox issue or a DM or Deuce issue.