Fixed minimumZoomScale

Fixed user should be able to scale image to the exact size of a square outline.
Conflicts:
	RSMoveAndScaleController.m
Fixed move and scale
Fixed move and scale
Fixed image frame and scrollerview contentSize
Merge branch 'master' of https://github.com/chinesejian/RSAvatarController into chinesejian-master

Conflicts:
	RSMoveAndScaleController.m