cannot change duration while sim is running
Merge branch 'disallow-duration-changes-while-running' into development
generated SimObject base class
implemented virtual update function
updated test
Merge branch 'create-base-sim-object' into development
generated ObjectManager class
implemented object addition and removal
updated tests
removed un-needed tests and improved others
better variable name for object manager tests
Merge branch 'create-object-manager' into development