Make Utilities.createSVGElement() and createElement() extensions of document

[shallawa]

    this.element = Utilities.createSVGElement("image", attrs, xlinkAttrs, stage.element);

can be

    this.element = document.createSVGElement("image", attrs, xlinkAttrs, stage.element);

And

    var row = Utilities.createElement("tr", {}, this.element);

can be

    var row = document.createHTMLElement("tr", {}, this.element);