IPHONE-75: Added some helper classes to help in navigation management implementation.
IPHONE-75: Re-implemented navigation history using ScreenReferenceStack object.
This removes dependance of navigation history on Navigate object (fromGroup/fromScreen properties) and provides a depth limit to the navigation history.
Removed fromGroup/fromScreen properties from Navigate, this was an artefact on how the console implemented navigation management and does not belong in the object model.
Started adding new ORNavigation model object to replace older Navigate
Fixed typo in comment
Added new ORScreen and ORGroup model objects. These will eventually replace Screen and Group legacy classes but for now they just inherit from them.
This act as a name alias, allowing to implement ORNavigation against new names so we won't need to change again later.
Implemented first part of ORNavigation : logical type (along with parser and unit test)
Started some work on ORNavigation to group or screen, but need some changes in other parts of framework before moving forward
Introducing ORModelObject base class, providing reference to Definition to all model objects
Updated deferred bindings to use ORModelObject as their target instead of ORWidget as bindings should work with any parsed object, not just widgets
Implemented ORNavigation to group and screen, including parsing and unit tests.
Cleanup to be done once ORScreen and ORGroup have been implemented.