VM window mode

enum _PRL_VM_WINDOW_MODE {
  PWM_DEFAULT_WINDOW_MODE = 0,
  PWM_WINDOWED_WINDOW_MODE = 1,
  PWM_FULL_SCREEN_WINDOW_MODE = 2,
  PWM_COHERENCE_WINDOW_MODE = 3,
  PWM_MODALITY_WINDOW_MODE = 4,
  PWM_HEADLESS_WINDOW_MODE = 5
};