Added Photo viewer scene with using the new OKIPhotoAssetViewController class.  Users can tap a photo in the album collection view to view the photo full screen.
NOTE: This currently only works on the iPhone version and in the default portrait orientation
Added photo viewing scene for iPad version.  There is currently a known issue with initial photo placement when transitioning to the photo scene in landscape orientation
- Fixed issue with initially displaying photo in photo scene while in landscape mode.  Photo is now initially properly centered, scaled and oriented.
- Photo scene now prefers to hide the status bar.  There is commented code to hide the navigation bar as well but is being left out until tap gesture recognition is enabled
Added tap gesture recognition to iPad version in order to toggle the visibility of the navigation bar in the photo viewing scene
- Added tap gesture recognition on iPhone version
- Changed the behavior of the status bar and navigation bar visibility of the photo viewing scene.  They are now both initially visible and their visibility is toggled together by user taps on the scene