ImageLoaderIndicator Objective-C Version
##ImageLoaderIndicator学习教程 ###How To Implement A Circular Image Loader Animation with CAShapeLayer http://www.raywenderlich.com/94302/implement-circular-image-loader-animation-cashapelayer
###使用CAShapeLayer来实现圆形图片加载动画[译] http://www.jianshu.com/p/16ef46c14515