Enhance DRL->RuleModel unmarshalling to handle modify() {...} block

Edson requested we enhance Drools Workbench to generate "modify()

{...}" blocks instead of the current use of "update()" so that property reactive fields work correctly.

Before we can complete the change we need to be able to handle the "modify() {...}

" block when rehydrating the RuleModel object from DRL used by the UI.