feat(pipe): added the Pipe decorator and the pipe property to View

BREAKING CHANGE:
    Instead of configuring pipes via a Pipes object, now you can configure them by providing the pipes property to the View decorator.

    @Pipe({
      name: 'double'
    })
    class DoublePipe {
      transform(value, args) { return value * 2; }
    }

    @View({
      template: '{{ 10 | double}}'
      pipes: [DoublePipe]
    })
    class CustomComponent {}

Closes #3572

modules/angular2/annotations.ts

@@ -12,6 +12,7 @@
 export {
   ComponentAnnotation,
   DirectiveAnnotation,
+  PipeAnnotation,
   LifecycleEvent
 } from './src/core/annotations/annotations';
 
@@ -43,5 +44,7 @@ export {
   ViewFactory,
   Query,
   QueryFactory,
-  ViewQuery
+  ViewQuery,
+  Pipe,
+  PipeFactory
 } from 'angular2/src/core/annotations/decorators';