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/core/src/linker/query_list.ts

@@ -14,7 +14,7 @@ import {getSymbolIterator} from '../facade/lang';
  * An unmodifiable list of items that Angular keeps up to date when the state
  * of the application changes.
  *
- * The type of object that {@link QueryMetadata} and {@link ViewQueryMetadata} provide.
+ * The type of object that {@link Query} and {@link ViewQueryMetadata} provide.
  *
  * Implements an iterable interface, therefore it can be used in both ES6
  * javascript `for (var i of items)` loops as well as in Angular templates with