SetDisplaysZombies
void SetDisplaysZombies(bool state);
fShelf->SetDisplaysZombies(true);
fDesktopShelf->SetDisplaysZombies(true);
SetDisplaysZombies(allowZombies);
fDeskShelf->SetDisplaysZombies(true);
fShelf -> SetDisplaysZombies(true);
fShelf->SetDisplaysZombies(true);