Some changes for correct work when contentView not scaling

Added properties: BOOL menuViewAlphaChangeable, CGFloat menuViewScaleValue.

CGAffineTransformTranslate was replaced by changing contentView's coordinate x depend on panGestureRecognize's velocity.x.

Properties contentViewInLandscapeOffsetCenterX and contentViewInPortraitOffsetCenterX replaced on contentViewInLandscapeOriginX and contentViewInPortraitOriginX respectively.