UIView Extension #1
var left:CGFloat{
    get{
        return self.frame.origin.x
    }
    set{
        self.frame = CGRectMake(newValue, self.frame.origin.y, self.frame.size.width, self.frame.size.height)
    }
}
var right:CGFloat{
    get{
        return self.frame.origin.x + self.frame.size.width
    }
    set{
        self.frame = CGRectMake(newValue - self.frame.size.width, self.frame.origin.y, self.frame.size.width, self.frame.size.height)
    }
}
var top:CGFloat{
    get{
        return self.frame.origin.y
    }
    set{
        self.frame = CGRectMake(self.frame.origin.x, newValue, self.frame.size.width, self.frame.size.height)
    }
}
var bottom:CGFloat{
    get{
        return self.frame.origin.y + self.frame.size.height
    }
    set{
        self.frame = CGRectMake(self.frame.origin.x, newValue - self.frame.size.height, self.frame.size.width, self.frame.size.height)
    }
}