refactor(core): remove …Metadata for all decorators and use the decorator directly.

BREAKING CHANGE:
- all `…Metadata` classes have been removed. Use the corresponding decorator
  as constructor or for `instanceof` checks instead.
- Example:
  * Before: `new ComponentMetadata(…)`
  * After: `new Component(…)`
- Note: `new Component(…)` worked before as well.

modules/@angular/compiler/src/ng_module_resolver.ts

@@ -6,25 +6,24 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {Injectable, NgModuleMetadata, Type} from '@angular/core';
+import {Injectable, NgModule, Type} from '@angular/core';
 
 import {isPresent, stringify} from './facade/lang';
 import {ReflectorReader, reflector} from './private_import_core';
 
-function _isNgModuleMetadata(obj: any): obj is NgModuleMetadata {
-  return obj instanceof NgModuleMetadata;
+function _isNgModuleMetadata(obj: any): obj is NgModule {
+  return obj instanceof NgModule;
 }
 
 /**
- * Resolves types to {@link NgModuleMetadata}.
+ * Resolves types to {@link NgModule}.
  */
 @Injectable()
 export class NgModuleResolver {
   constructor(private _reflector: ReflectorReader = reflector) {}
 
-  resolve(type: Type<any>, throwIfNotFound = true): NgModuleMetadata {
-    const ngModuleMeta: NgModuleMetadata =
-        this._reflector.annotations(type).find(_isNgModuleMetadata);
+  resolve(type: Type<any>, throwIfNotFound = true): NgModule {
+    const ngModuleMeta: NgModule = this._reflector.annotations(type).find(_isNgModuleMetadata);
 
     if (isPresent(ngModuleMeta)) {
       return ngModuleMeta;