Fixed some orientation bugs

Change preview orientation as device rotate
Bug fixed: Capturing image always use default orientation
Bug fixed: Wrong orientation when capturing video
Bug fixed: Capturing video without rotating once, will produce video with wrong orientation

Since the default orientation of camera is AVCaptureVideoOrientationLandscapeRight,
the default orientation of video output should be the same, not portrait
Merge pull request #8 from b123400/master

Bugs fixed for wrong orientation