Add benchmark tests for AB or BC system.
Add various benchmark cases into todo.
Add tests for Lift system.
Modify benchmark test names and simplify cmake file inclusions.
Moving Complex scenario into a new directory named after the risk analysis class at UW
Give better names to complex cases from NE574 class example.
Do the same renaming in benchmark test inputs.
Add benchmark tests for the example from ne574 class.
Revert cmake simplification due to possible TravisCI problems.
Refactor MC set combination code with General Fault Tree set combination
code.
Correct parent setting for events.
Add benchmark tests for TwoTrain system.
Add benchmark tests for Three Levels case from OpenFTA.
Update docs and todo list.
Move to pass by reference for Superset classes.
Return and accept by reference in event classes.
Pass by reference for Expandsets function in fault tree class.
Add transfer gate benchmark tests from OpenFTA.
Add benchmark tests for Theatre case from OpenFTA.
Update todo list after introducing new benchmark tests.