Different notification message text for each client

I have created a patch to allow the email notification messages (new ticket, updated ticket, denied mail) to be different for each client. The mail text settings page has been altered to display a fieldset for each active client which contains the mail texts for each notification type. Each client's notifications now have Drupal variable names which follow the format support_mail_client_{clid}_{message-key}_{body/subject}.

These updates should work immediately, but the old mail text variables are left in the database.

The patch will follow.