Reorganized FakeExtVM class into .h and .cpp file. Added state class member in order to test CREATE and CALL. Added system operations test.

I can put .h and .cpp together again. The reason I did this, was that I needed to declare the FakeExtVM as a friend to the state class and therefore wanted to include vm.h. I also thought it would be a more clear design. But because of some forward declarations of the state class that gave a lot of "ambigious definition" errors, my solution now is the forward declaration of the FakeExtVM class in state.h , so I don't need that seperation of vm.h and vm.cpp anymore.