A function to create a new operator screen
OptionalgenerateA function that will generate the urscript for the operator screen.
OptionalupgradeThis function is called to upgrade an operator screen when the data model has been changed. For example, if you have added a new mandatory field to your OperatorScreen, this function should be used to give a default value to the existing screen
OptionalvalidatorA function that returns if the operator screen is valid. If false, the operator screen icon will be marked in the invalid colour, and the program cannot be played
OperatorScreenBehaviors describes the possible behaviors defined by operator screens. The object will be registered by calling registerOperatorScreenBehavior