ZENGINE: Make ZEngine::_workingWindow and ZEngine::_pixelFormat public
ZENGINE: Convert ScriptManager::_activeNodes to normal pointers instead of SharedPtrs
ZENGINE: Make MouseEvent purely virtual
ZENGINE: Make Control purely virtual
ZENGINE: Keep a member variable ZEngine pointer instead of passing it in every process()
ZENGINE: Have PushToggleControl inherit from MouseEvent and handle the methods internally.

Rather than creating an instance of MouseEvent and passing argument around.
ZENGINE: Convert _mouseEvents to pointers since MouseEvent is now abstract
ZENGINE: Change variable name to match its purpose
ZENGINE: Fix error: decrementing instead of incrementing
ZENGINE: Fix signed/unsigned mismatch
ZENGINE: Check if we can use getNextFrame() or getPreviousFrame() before using getFrameData()
ZENGINE: Add TODO's about the verbosity of the frame decoding overflow warning
ZENGINE: Fix memory leak

We no longer use SharedPtr
ZENGINE: Add note about _activeNodes
ZENGINE: Add console method to dump all .lev files
ZENGINE: Partially implement LeverControl