A subclass of UIImageView which has a progress view on it.
##NOTICE ####Currently, it should be rounded, so,just make the width and height equal.But I will fix this lately. ####The alpha of the mask couldn't be set directly but I will add this function as soon as possible. ####The progress label can be hidden but I didn't add this interface now, you should do it manually
##USAGE ###It can be created by Code and Interface Builder. ####make the mask the main color of the image, this function will be added after I am sure it works fine! -(void)setInverseEnable:(BOOL)enable NS_UNAVAILABLE;
####set the progress shown on the image view -(void)setProgress:(float)progress;
##Preview
