feat(router): add support for hash-based location

Closes #2555

modules/angular2/src/router/hash_location_strategy.ts

@@ -0,0 +1,32 @@
+import {DOM} from 'angular2/src/dom/dom_adapter';
+import {Injectable} from 'angular2/di';
+import {LocationStrategy} from './location_strategy';
+import {EventListener, History, Location} from 'angular2/src/facade/browser';
+
+@Injectable()
+export class HashLocationStrategy extends LocationStrategy {
+  private _location: Location;
+  private _history: History;
+
+  constructor() {
+    super();
+    this._location = DOM.getLocation();
+    this._history = DOM.getHistory();
+  }
+
+  onPopState(fn: EventListener): void {
+    DOM.getGlobalEventTarget('window').addEventListener('popstate', fn, false);
+  }
+
+  getBaseHref(): string { return ''; }
+
+  path(): string { return this._location.hash; }
+
+  pushState(state: any, title: string, url: string) {
+    this._history.pushState(state, title, '#' + url);
+  }
+
+  forward(): void { this._history.forward(); }
+
+  back(): void { this._history.back(); }
+}