Fix for iOS 8 iPad hiding status bar when clicking on image in News Gallery.
Fix for iOS 8 iPad Image Gallery status bar text black and not hiding when clicking image.

Fix for #233
setNeedsStatusBarAppearanceUpdate is supported on iOS 7 and up.  respondsToSelector is not needed here.
Merge pull request #234 from MIT-Mobile/3.6/news-gallery-fixes

3.6/news gallery fixes