Camera/multiple instances

Resolves Issue #389

    cam = Camera()
    cam.getImage().show()

    cam1 = Camera()
    cam1.getImage().show()

Supports multiple cameras also.

    cam = Camera(1)
    cam.getImage().show()

    cam1 = Camera(1)
    cam1.getImage().show()


    cam2 = Camera(2)
    cam2.getImage().show()

    cam2 = Camera(2)
    cam1.getImage().show()

If default index is 0, this will also work

    cam = Camera(0)
    cam.getImage().show()

    cam1 = Camera()
    cam1.getImage().show()

And this too

    cam = Camera()
    cam.getImage().show()

    cam1 = Camera(0)
    cam1.getImage().show()

If default index is 1, this will also work

    cam = Camera(1)
    cam.getImage().show()

    cam1 = Camera()
    cam1.getImage().show()

And this too

    cam = Camera()
    cam.getImage().show()

    cam1 = Camera(1)
    cam1.getImage().show()