feat(core): provide support for relative assets for components

Assets defined for `templateUrl` and `styleUrls` can now be loaded
in relative to where the component file is placed so long as the
`moduleId` is set within the component annotation.

Closes #5634

Closes #5634

modules/angular2/test/public_api_spec.ts

@@ -1196,6 +1196,9 @@ var NG_ALL = [
   'UpperCasePipe.transform()',
   'UrlResolver',
   'UrlResolver.resolve()',
+  'getUrlScheme()',
+  'PACKAGE_ROOT_URL',
+  'DEFAULT_PACKAGE_URL_PROVIDER',
   'Validators#compose()',
   'Validators#composeAsync()',
   'Validators#nullValidator()',