Initialize common controls and COM, and register the default window class. Idempotent; safe to call before creating any windows.
Post a quit request to the message loop with the given exit code.
Run the Win32 message loop until WM_QUIT. Returns the exit code carried by the quit message.
The process-wide application instance (created on first access).
The application object. Use Application.instance to obtain it, call initialize() once at startup, then run() to enter the message loop.