Update typescript, webpack, and asset building

js/src/webtty.ts

@@ -62,8 +62,8 @@ export class WebTTY {
 
     open() {
         let connection = this.connectionFactory.create();
-        let pingTimer: number;
-        let reconnectTimeout: number;
+        let pingTimer: NodeJS.Timeout;
+        let reconnectTimeout: NodeJS.Timeout;
 
         const setup = () => {
             connection.onOpen(() => {

js/src/xterm.ts

@@ -12,7 +12,7 @@ export class Xterm {
 
     message: HTMLElement;
     messageTimeout: number;
-    messageTimer: number;
+    messageTimer: NodeJS.Timeout;
 
 
     constructor(elem: HTMLElement) {