feat(debug): replace DebugElement with new Debug DOM

Now, using `ng.probe(element)` in the browser console returns
a DebugElement when in dev mode.

`ComponentFixture#debugElement` also returns a new DebugElement.

Breaking Change:

This is a breaking change for unit tests. The API for the DebugElement
has changed. Now, there is a DebugElement or DebugNode for every node
in the DOM, not only nodes with an ElementRef. `componentViewChildren` is
removed, and `childNodes` is a list of ElementNodes corresponding to every
child in the DOM. `query` no longer takes a scope parameter, since
the entire rendered DOM is included in the `childNodes`.

Before:

```
componentFixture.debugElement.componentViewChildren[0];
```

After
```
// Depending on the DOM structure of your component, the
// index may have changed or the first component child
// may be a sub-child.
componentFixture.debugElement.children[0];
```

Before:

```
debugElement.query(By.css('div'), Scope.all());
```

After:

```
debugElement.query(By.css('div'));
```

Before:

```
componentFixture.debugElement.elementRef;
```

After:

```
componentFixture.elementRef;
```

modules/angular2/platform/browser.ts

@@ -1,8 +1,8 @@
 export {AngularEntrypoint} from 'angular2/src/core/angular_entrypoint';
 export {
   BROWSER_PROVIDERS,
-  ELEMENT_PROBE_BINDINGS,
   ELEMENT_PROBE_PROVIDERS,
+  ELEMENT_PROBE_PROVIDERS_PROD_MODE,
   inspectNativeElement,
   BrowserDomAdapter,
   By,

modules/angular2/platform/browser_static.ts

@@ -1,8 +1,8 @@
 export {AngularEntrypoint} from 'angular2/src/core/angular_entrypoint';
 export {
   BROWSER_PROVIDERS,
-  ELEMENT_PROBE_BINDINGS,
   ELEMENT_PROBE_PROVIDERS,
+  ELEMENT_PROBE_PROVIDERS_PROD_MODE,
   inspectNativeElement,
   BrowserDomAdapter,
   By,

modules/angular2/platform/common_dom.ts

@@ -12,4 +12,4 @@ export {
   EventManagerPlugin
 } from 'angular2/src/platform/dom/events/event_manager';
 export * from 'angular2/src/platform/dom/debug/by';
-export * from 'angular2/src/platform/dom/debug/debug_element_view_listener';
+export * from 'angular2/src/platform/dom/debug/ng_probe';