- Always use a UIViewController, even if window is not resizable.
- Let non-resizable windows still flip over, so user can hold device with the
correct orientation, but upside down, if that's more comfortable.
- Don't set the UIScreen unless we're forced to, as it resets some state.
- Minor correction with conventions for -[self init] tapdance.

--HG--
extra : rebase_source : d1b861f1174282eccb34f5efd183b03f6efcc2fa