added frontend displaying of the delivery date field
saving of the delivery date as an additional order attribute
added displaying of the delivery date in the backend order list
added displaying of the delivery date in the backend order details
refactoring of the components
refactoring of observer methods - created a new observer component to handle them
refactoring
removed factory class
added class comment
added source headers
fixed scrutinizer issues
refactoring
refactoring
Merge pull request #1 from sitewards/delivery-date

Delivery date