v2.2.0

• Added gesture to exit full mode by scrolling up/down or zooming out.
  Added corresponding setting (enabled by default).
• Added CircleImageView and CircleGestureImageView to show and animate rounded images.
• Added animation duration setting, default duration is changed from 250 to 300 ms.
• Added state source listener (whether image is idle, dragged by user or updated by animation).
• Added debug overlay.
• Better clipping when animating rotated images.
• Fixed fast quick scale issue (image may be flipped).
• Fixed scroll when zoomed out with bounds restrictions disabled.
• Fixed wrap_content handling for GestureFrameLayout.