Fixes #3222 - supports [submitted] token in Shipment Form submitted copy
Changes per #3237 review
Merge pull request #3237 from aaronschachter/shipment_created

Support [submitted] token in Shipment Form submitted copy
Adds isset checks to avoid PHP Notice undefined index
Merge pull request #3238 from aaronschachter/php_forever

Adds isset checks to avoid PHP Notice undefined index