fix: export ShadowDomStrategy and NativeShadowDomStrategy

Fixes angular#1510

Author: pkozlowski-opensource

Diff for: modules/angular2/core.js

@@ -15,7 +15,9 @@ export * from './src/core/compiler/query_list';
 export * from './src/core/compiler/compiler';
 
 // TODO(tbosch): remove this once render migration is complete
-export * from 'angular2/src/render/dom/compiler/template_loader';
+export * from './src/render/dom/compiler/template_loader';
+export * from './src/render/dom/shadow_dom/shadow_dom_strategy.js';
+export * from './src/render/dom/shadow_dom/native_shadow_dom_strategy';
 export * from './src/core/compiler/dynamic_component_loader';
 export {ElementRef, ComponentRef} from './src/core/compiler/element_injector';
 export * from './src/core/compiler/view';