respect the autorotate-policy of the contained view controller

in shouldAutorotateToInterfaceOrientation:, attempt to ascertain
whether _viewController responds to the same selector, and return that
value if so, or fall back to the original YES

in deviceOrientationDidChange:, attempt to ascertain whether
_viewController responds to shouldAutorotateToInterfaceOrientation:,
and if it does see if the deviceOrientation is supported, and whether
or not it's even necessary to attempt to call setupView again.
Merge pull request #34 from johnkdoe/master

respect the autorotate-policy of the contained view controller