Support different Orientations. See #7

This should handle all screen orientations correctly. (Not entirely sure about portrait upsidedown, as I couldn't get the demo to rotate upside down, but it should be correct.)

I changed the landscape navigation bar height, as it was not high enough for me. This way it is.
Current problem is that when the device is rotated, while a notification is displayed, that notification  will not change it's width. But as I'm not quite sure how to handle that, here's the current progress, as it already makes things better.