chore(packaging): move files to match target file structure

modules/angular2/di.js

@@ -0,0 +1,7 @@
+export {Inject, InjectPromise, InjectLazy, DependencyAnnotation} from './src/annotations';
+export {Injector} from './src/injector';
+export {Binding, Dependency, bind} from './src/binding';
+export {Key, KeyRegistry} from './src/key';
+export {KeyMetadataError, NoProviderError, ProviderError, AsyncBindingError, CyclicDependencyError,
+  InstantiationError, InvalidBindingError, NoAnnotationError} from './src/exceptions';
+export {OpaqueToken} from './src/opaque_token';