Need OuterHTML polyfill for SVGElements on Edge and IE

[Twiknight]

FragmentFactory would break when working with svg Elements when it tries to cache an element on IE or MS-Edge due to lack of SVGElement.outerHTML support.

code: https://github.com/vuejs/vue/blob/dev/src/fragment/factory.js Line:32

As MS has already stopped adding feature to any version of IE, a possible solution might be a polyfill.

sample code (borrowed from http://stackoverflow.com/questions/12592417/outerhtml-of-an-svg-element/20559830#20559830):

Object.defineProperty(SVGElement.prototype, 'outerHTML', {
    get: function () {
        var $node, $temp;
        $temp = document.createElement('div');
        $node = this.cloneNode(true);
        $temp.appendChild($node);
        return $temp.innerHTML;
    },
    enumerable: false,
    configurable: true
});