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/test/platform/browser/debug/debug_element_view_listener_spec.ts

@@ -1,71 +0,0 @@
-import {
-  AsyncTestCompleter,
-  beforeEach,
-  ddescribe,
-  xdescribe,
-  describe,
-  dispatchEvent,
-  expect,
-  iit,
-  inject,
-  beforeEachProviders,
-  it,
-  xit,
-  TestComponentBuilder,
-} from 'angular2/testing_internal';
-import {global} from 'angular2/src/facade/lang';
-import {provide, Component, Directive, Injectable, View} from 'angular2/core';
-import {inspectNativeElement} from 'angular2/platform/browser';
-import {IS_DART} from 'angular2/src/facade/lang';
-
-@Component({selector: 'my-comp'})
-@View({directives: []})
-@Injectable()
-class MyComp {
-  ctxProp: string;
-}
-
-export function main() {
-  describe('element probe', function() {
-    it('should return a TestElement from a dom element',
-       inject([TestComponentBuilder, AsyncTestCompleter], (tcb: TestComponentBuilder, async) => {
-         tcb.overrideTemplate(MyComp, '<div some-dir></div>')
-             .createAsync(MyComp)
-             .then((componentFixture) => {
-               expect(inspectNativeElement(componentFixture.debugElement.nativeElement)
-                          .componentInstance)
-                   .toBeAnInstanceOf(MyComp);
-
-               async.done();
-             });
-       }));
-
-    it('should clean up whent the view is destroyed',
-       inject([TestComponentBuilder, AsyncTestCompleter], (tcb: TestComponentBuilder, async) => {
-         tcb.overrideTemplate(MyComp, '')
-             .createAsync(MyComp)
-             .then((componentFixture) => {
-               componentFixture.destroy();
-               expect(inspectNativeElement(componentFixture.debugElement.nativeElement)).toBe(null);
-
-               async.done();
-             });
-
-       }));
-
-    if (!IS_DART) {
-      it('should provide a global function to inspect elements',
-         inject([TestComponentBuilder, AsyncTestCompleter], (tcb: TestComponentBuilder, async) => {
-           tcb.overrideTemplate(MyComp, '')
-               .createAsync(MyComp)
-               .then((componentFixture) => {
-                 expect(global['ng']['probe'](componentFixture.debugElement.nativeElement)
-                            .componentInstance)
-                     .toBeAnInstanceOf(MyComp);
-
-                 async.done();
-               });
-         }), 1000);
-    }
-  });
-}