'Create and return a clone of the turtle.
No argument.
Create and return a clone of the turtle with same position, heading
and turtle properties.
Example (for a Turtle instance named mick):
mick = Turtle()
joe = mick.clone()'

def clone(self):

    screen = self.screen
    self._newLine(self._drawing)
    turtle = self.turtle
    self.screen = None
    self.turtle = None
    q = deepcopy(self)
    self.screen = screen
    self.turtle = turtle
    q.screen = screen
    q.turtle = _TurtleImage(screen, self.turtle.shapeIndex)
    screen._turtles.append(q)
    ttype = screen._shapes[self.turtle.shapeIndex]._type
    if (ttype == 'polygon'):
        q.turtle._item = screen._createpoly()
    elif (ttype == 'image'):
        q.turtle._item = screen._createimage(screen._shapes['blank']._data)
    elif (ttype == 'compound'):
        q.turtle._item = [screen._createpoly() for item in screen._shapes[self.turtle.shapeIndex]._data]
    q.currentLineItem = screen._createline()
    q._update()
    return q
