refactor(pipes): use Injector instead of pipe factories for pipe instantiation

BREAKING CHANGE
    - Pipe factories have been removed.
    - PIpe names to pipe implementations are 1-to-1  instead of 1-to-*

 Before:
     class DateFormatter {
         transform(date, args){}
     }

     class DateFormatterFactory {
       supporst(obj) { return true; }
       create(cdRef) { return new DateFormatter(); }
     }
     new Pipes({date: [new DateFormatterFactory()]})

After
    class DateFormatter {
      transform(date, args){}
    }
    new Pipes({date: DateFormatter})

modules/angular2/change_detection.ts

@@ -29,8 +29,5 @@ export {
   KeyValueDiffers,
   KeyValueDiffer,
   KeyValueDifferFactory,
-  PipeFactory,
-  BasePipe,
-  NullPipe,
-  NullPipeFactory
+  BasePipe
 } from 'angular2/src/change_detection/change_detection';