Global import of rxjs lib

public/docs/_examples/toh-6/ts/app/hero-search.service.ts

@@ -1,7 +1,7 @@
 // #docregion
 import { Injectable }     from '@angular/core';
 import { Http, Response } from '@angular/http';
-import { Observable } from 'rxjs';
+import { Observable } from 'rxjs/Observable';
 
 import { Hero }           from './hero';