angular2 universal updated to 0.70.x

[PatrickJS]

• beta.9 update
• better prerendering support
• support for many applications on server-side
• polyfill removed now as import 'angular2-universal-preview/polyfills';

see universal-starter for changes https://github.com/angular/universal-starter/blob/master/src/server.ts

[jeffbcross]

thx @gdi2290 for your concern.