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/core.dart

@@ -15,7 +15,7 @@ export './src/core/application_tokens.dart' show APP_ID,
 export './src/core/zone.dart';
 export './src/core/render.dart';
 export './src/core/linker.dart';
-export './src/core/debug/debug_element.dart' show DebugElement,
+export './src/core/debug/debug_node.dart' show DebugElement,
   Scope,
   inspectElement,
   asNativeElements;

modules/angular2/core.ts

@@ -20,12 +20,7 @@ export {
 export * from './src/core/zone';
 export * from './src/core/render';
 export * from './src/core/linker';
-export {
-  DebugElement,
-  Scope,
-  inspectElement,
-  asNativeElements
-} from './src/core/debug/debug_element';
+export {DebugElement, asNativeElements} from './src/core/debug/debug_node';
 export * from './src/core/testability/testability';
 export * from './src/core/change_detection';
 export * from './src/core/platform_directives_and_pipes';

modules/angular2/examples/core/debug/ts/debug_element/debug_element.ts

@@ -1,16 +1,8 @@
-import {DebugElement, Scope} from 'angular2/core';
+import {DebugElement} from 'angular2/core';
 
 var debugElement: DebugElement;
 var predicate;
 
 // #docregion scope_all
-debugElement.query(predicate, Scope.all);
-// #enddocregion
-
-// #docregion scope_light
-debugElement.query(predicate, Scope.light);
-// #enddocregion
-
-// #docregion scope_view
-debugElement.query(predicate, Scope.view);
+debugElement.query(predicate);
 // #enddocregion

modules/angular2/examples/platform/dom/debug/ts/by/by.ts

@@ -1,17 +1,17 @@
 import {By} from 'angular2/platform/browser';
-import {DebugElement, Scope} from 'angular2/core';
+import {DebugElement} from 'angular2/core';
 
 var debugElement: DebugElement;
 class MyDirective {}
 
 // #docregion by_all
-debugElement.query(By.all(), Scope.all);
+debugElement.query(By.all());
 // #enddocregion
 
 // #docregion by_css
-debugElement.query(By.css('[attribute]'), Scope.all);
+debugElement.query(By.css('[attribute]'));
 // #enddocregion
 
 // #docregion by_directive
-debugElement.query(By.directive(MyDirective), Scope.all);
+debugElement.query(By.directive(MyDirective));
 // #enddocregion

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';

modules/angular2/src/core/application_common_providers.ts

@@ -15,7 +15,6 @@ import {ResolvedMetadataCache} from 'angular2/src/core/linker/resolved_metadata_
 import {AppViewManager} from './linker/view_manager';
 import {AppViewManager_} from "./linker/view_manager";
 import {ViewResolver} from './linker/view_resolver';
-import {AppViewListener} from './linker/view_listener';
 import {DirectiveResolver} from './linker/directive_resolver';
 import {PipeResolver} from './linker/pipe_resolver';
 import {Compiler} from './linker/compiler';
@@ -32,7 +31,6 @@ export const APPLICATION_COMMON_PROVIDERS: Array<Type | Provider | any[]> = CONS
   APP_ID_RANDOM_PROVIDER,
   ResolvedMetadataCache,
   new Provider(AppViewManager, {useClass: AppViewManager_}),
-  AppViewListener,
   ViewResolver,
   new Provider(IterableDiffers, {useValue: defaultIterableDiffers}),
   new Provider(KeyValueDiffers, {useValue: defaultKeyValueDiffers}),