Adds init(copy) method to all visible objects

[traviskirton]

Fixes: #603

Tested with the following:

override func setup() {
    movieCopy()
}

func movieCopy() {
    let m = Movie("halo.mp4")!
    m.constrainsProportions = true
    m.width = 160
    canvas.add(m)

    let m2 = Movie(copy: m)!
    m2.center = canvas.center
    canvas.add(m2)
}

func imageCopy() {
    let i = Image("chop")!
    canvas.add(i)
    i.shadow.opacity = 0.85
    i.shadow.radius = 10.0
    i.shadow.color = C4Blue

    i.border.color = C4Purple
    i.border.width = 10.0
    i.border.radius = 5.0

    let m = View(frame: Rect(-20, -20, 200, 200))
    m.backgroundColor = white
    i.mask = m

    i.transform = Transform.makeScale(0.5, 0.5)
    i.rotation = M_PI_4

    i.apply(DotScreen())
    canvas.add(i)

    wait(0.1) {
        let newI = Image(copy: i)
        newI.center = self.canvas.center
        self.canvas.add(newI)
    }
}

func shapeCopy() {
    let c = Circle(center: Point(100,100), radius: 50.0)
    c.backgroundColor = C4Pink

    c.shadow.opacity = 0.85
    c.shadow.radius = 10.0
    c.shadow.color = C4Blue

    c.border.color = C4Purple
    c.border.width = 10.0
    c.border.radius = 5.0

    let m = View(frame: Rect(50, 50, 100, 100))
    m.backgroundColor = white
    c.mask = m

    c.transform = Transform.makeScale(0.5, 0.5)
    c.rotation = M_PI_4
    canvas.add(c)

    let newC = Shape(copy: c)
    newC.center = canvas.center
    canvas.add(newC)
}

func viewCopy() {
    let v = View(frame:Rect(0, 0, 100, 100))
    v.backgroundColor = C4Pink

    v.shadow.opacity = 0.85
    v.shadow.radius = 10.0
    v.shadow.color = C4Blue

    v.border.color = C4Purple
    v.border.width = 10.0
    v.border.radius = 5.0

    let m = View(frame: Rect(50, 50, 100, 100))
    m.backgroundColor = white
    v.mask = m

    v.transform = Transform.makeScale(0.5, 0.5)
    v.rotation = M_PI_4
    canvas.add(v)

    let newV = View(copyView: v)
    newV.center = canvas.center
    canvas.add(newV)
}

func viewCopyShapeMask() {
    let v = View(frame:Rect(0, 0, 100, 100))
    v.backgroundColor = C4Pink

    v.shadow.color = C4Blue
    v.shadow.radius = 10.0
    v.shadow.opacity = 0.85

    v.border.color = C4Purple
    v.border.width = 10.0
    v.border.radius = 5.0

    let m = Circle(center: Point(), radius: 50.0)
    v.mask = m

    v.transform = Transform.makeScale(0.5, 0.5)
    v.rotation = M_PI_4
    canvas.add(v)

    let newV = View(copyView: v)
    newV.center = canvas.center
    canvas.add(newV)
}

func viewCopyImageMask() {
    let v = View(frame:Rect(0, 0, 100, 100))
    v.backgroundColor = C4Pink

    v.shadow.color = C4Blue
    v.shadow.radius = 10.0
    v.shadow.opacity = 0.85

    v.border.color = C4Purple
    v.border.width = 10.0
    v.border.radius = 5.0

    let g = Gradient(frame: v.frame, colors: [C4Pink, clear])
    let m = g.render()
    m?.center = Point()
    v.mask = m

    v.transform = Transform.makeScale(0.5, 0.5)
    v.rotation = M_PI_4
    canvas.add(v)

    let newV = View(copyView: v)
    newV.center = canvas.center
    canvas.add(newV)
}