message: fixed errors in polyfills
diff: @@ -2,7 +2,7 @@ export interface MatchesMethod {
  (css: string): boolean
  }
  -export interface OldElement extends HTMLElement {
  +export interface OldElement extends Element {
  matchesSelector?: MatchesMethod,
  mozMatchesSelector?: MatchesMethod,
  msMatchesSelector?: MatchesMethod,
  @@ -21,8 +21,8 @@ if (window) {
  // Element.prototype.closest
  if (!ElementProto.closest) {
  - ElementProto.closest = function(css: string): HTMLElement | null {
  - let node: HTMLElement = this;
  + ElementProto.closest = function(css: string): Element | null {
  + let node: Element = this;
  while (node) {
  if (node.matches(css)) return node;
  else node = node.parentElement;
  