ios7 bug is fixed.
scroll view bounds is calculated regarding background of nav bar, status bar and toolbar.
But, there is remaining issues.
1. when resizing, edge touch movement broke anchor point. thus after move, fix rect size again.
2. rotation is not accurate.
resize logic changed from animation to timer backed like apple native photo app crop.
add public property rotationAngle and set value at done button clicked.
purpose of saving cropRect and rotationAngle is save crop info for later respawn with original image.