WebShipping Demo: Open existing shipment + more events

What to expect and how to use this demo

- Click "Open Web Shipping"
- Note that "new shipment" form displayed. "Ship" button enabled.
- Ship
- Close shipping form
- Note that "shipment_completed" was called and "ShipmentId" text field has a value now
- Click "Open Web Shipping" again
- Note that "shipped" form is displayed. "Void" button available on the right. "Ship" button is disabled.
- Click "Void"
- Note that "void" event was called with the same "ShipmentId"
- Go to the "Shipped" folder, click "reprint" on any of the shipment
- Note that "reprint" event was called