refactor(Directive): drop moduleId

moduleId is only used by components to resolve urls.
Directives have no templates and do not need moduleId.
Closes #5873

modules/angular2/test/public_api_spec.ts

@@ -923,7 +923,6 @@ var NG_CORE = [
   'Directive.events',
   'Directive.exportAs',
   'Directive.host',
-  'Directive.moduleId',
   'Directive.inputs',
   'Directive.properties',
   'Directive.queries',
@@ -935,7 +934,6 @@ var NG_CORE = [
   'DirectiveMetadata.events',
   'DirectiveMetadata.exportAs',
   'DirectiveMetadata.host',
-  'DirectiveMetadata.moduleId',
   'DirectiveMetadata.inputs',
   'DirectiveMetadata.properties',
   'DirectiveMetadata.queries',