Define a way to query if a property is in scope

After resolving QTBUG-11606 accessing any property that is not currently in the scope will throw ReferenceError. I have run into this problem quite often when trying to create modular code that needs to interface with surrounding scopes. Rather than polluting the code with try-catch blocks (which for property assignment is downright ugly), it would be nice to have a way of telling if a property is available in the current scope or not. I.e Qt.canResolveProperty("orientation") or something similar.