docs(router): move examples into own file and add tests

Closes #4620

modules/angular2/examples/router/ts/reuse/reuse_example.ts

@@ -0,0 +1,56 @@
+import {bootstrap, Component, bind} from 'angular2/angular2';
+import {
+  CanActivate,
+  RouteConfig,
+  ComponentInstruction,
+  ROUTER_DIRECTIVES,
+  APP_BASE_HREF,
+  CanReuse,
+  RouteParams,
+  OnReuse
+} from 'angular2/router';
+
+
+// #docregion reuseCmp
+@Component({
+  selector: 'my-cmp',
+  template: `
+    <div>hello {{name}}!</div>
+    <div>message: <input id="message"></div>
+  `
+})
+class MyCmp implements CanReuse,
+    OnReuse {
+  name: string;
+  constructor(params: RouteParams) { this.name = params.get('name') || 'NOBODY'; }
+
+  canReuse(next: ComponentInstruction, prev: ComponentInstruction) { return true; }
+
+  onReuse(next: ComponentInstruction, prev: ComponentInstruction) {
+    this.name = next.params['name'];
+  }
+}
+// #enddocregion
+
+
+@Component({
+  selector: 'example-app',
+  template: `
+    <h1>Say hi to...</h1>
+    <a [router-link]="['/HomeCmp', {name: 'naomi'}]" id="naomi-link">Naomi</a> |
+    <a [router-link]="['/HomeCmp', {name: 'brad'}]" id="brad-link">Brad</a>
+    <router-outlet></router-outlet>
+  `,
+  directives: [ROUTER_DIRECTIVES]
+})
+@RouteConfig([
+  {path: '/', component: MyCmp, as: 'HomeCmp'},
+  {path: '/:name', component: MyCmp, as: 'HomeCmp'}
+])
+class AppCmp {
+}
+
+
+export function main() {
+  return bootstrap(AppCmp, [bind(APP_BASE_HREF).toValue('/angular2/examples/router/ts/reuse')]);
+}