Orders do not send to mailchimp if a user is subscribed to a list

In its current state an order does not get sent to mailchimp unless the purchase was initiated by an email account. This patch checks to see if a user is already subscribed to a mailing list. If the user is subscribed the order is sent to mailchimp to be added. This patch also contains the patch from #759980: Module fails to update MailChimp ECommerce360 conversion information after sales