1. Bring in ‘showsPlaceholder’
2. Rendering Event indicators by image instead of CALayer
3. Using FSCalendarAnimator to control animations
4. Update Examples
5. Code clean
1. Subclass UICollectionViewFlowLayout for decouple
2. Subclass UICollectionView, to erase annoying warning caused by
‘automaticallyAdjustsScrollViewInsets’ of UIViewController