Add new scripting API to set a mail type

    /**
     * Specifies what type of email is being sent. This is useful for applications to sepcify a type when they send
     * mail. This allows (for example) to filter these emails in the Mail Sender Status Admin UI.
     *
     * @param mailType the type of mail being sent (e.g "Watchlist", "Reset Password", "Send Page by Mail", etc)
     */
    public void setType(String mailType)