Deactivate redefined graphnodes

1. Graphanodes that are redefined should be inactive
2. Check for graphnode redefinition in the same scope
Refactor graphnode redefinition routine to HandleGraphNodeRedefinitionInScope()
Liverunner testcase to simulate revit node force-execution bug

Simulates the defect from:
http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-4642
Merge pull request #2469 from junmendoza/VMStability

Deactivate redefined graphnodes