Allows you to use templates for custom elements in IE11. Wrote this to be able to use webcomponents/shadycss

template-polyfill.js

(function (document) {
    if ('content' in document.createElement('template')) {
        return;
    }

    Object.defineProperty(HTMLUnknownElement.prototype, 'content', {
        enumerable: false,
        configurable: true,
        get: function() {
            if (this.localName !== 'template') {
                return;
            }

            if (!this._content) {
                this._content = document.createDocumentFragment();

                for (var i = 0; i < this.childNodes.length; i++) {
                    this._content.appendChild(this.childNodes[i].cloneNode(true));
                }
            }

            return this._content;
        }
    });
})(window.document);