Use different layout for Landscape orientation

[murraycu]

On Android, on tablets (like iPads) we use the normal layout for portrait orientation. For instance:
https://github.com/murraycu/android-galaxyzoo/blob/master/google_play_store_graphics/screenshots_tablet_10inch/screenshot_nexus10_api21_portrait_classify_spirals.png

But for landscape orientation on Android tablets we put the questions at the side, like so:
https://github.com/murraycu/android-galaxyzoo/blob/master/google_play_store_graphics/screenshots_tablet_10inch/screenshot_nexus10_api21_landscape_classify_first.png

This lets us see the image as large as possible without stretching the answer buttons too much horizontally. The end result doesn't look ideal, but we should probably do the same for iPad, at least until we think of something better.

[murraycu]

I'm playing with alternative layouts for iPad in the ipad branch:
https://github.com/murraycu/ios-galaxyzoo/tree/ipad

These screenshots shows how it might look with the image and questions side by side, though I haven't yet managed to get the questions part all neatly arranged at the top of the screen.

I don't think this works entirely on Android:
https://github.com/murraycu/android-galaxyzoo/blob/master/google_play_store_graphics/screenshots_tablet_10inch/screenshot_nexus10_api21_landscape_classify_first.png

So we might want to just use the regular iPhone layout on iPad. For instance:
https://github.com/murraycu/ios-galaxyzoo/blob/master/screenshots_for_translators/screenshot_ipad_air2_classify_portrait.png
and
https://github.com/murraycu/ios-galaxyzoo/blob/master/screenshots_for_translators/screenshot_ipad_air2_classify_landscape.png