refactor(core): change module semantics

This contains major changes to the compiler, bootstrap of the platforms
and test environment initialization.

Main part of #10043
Closes #10164

BREAKING CHANGE:
- Semantics and name of `@AppModule` (now `@NgModule`) changed quite a bit.
  This is actually not breaking as `@AppModules` were not part of rc.4.
  We will have detailed docs on `@NgModule` separately.
- `coreLoadAndBootstrap` and `coreBootstrap` can't be used any more (without migration support).
  Use `bootstrapModule` / `bootstrapModuleFactory` instead.
- All Components listed in routes have to be part of the `declarations` of an NgModule.
  Either directly on the bootstrap module / lazy loaded module, or in an NgModule imported by them.

modules/@angular/core/index.ts

@@ -23,8 +23,8 @@ export {DebugElement, DebugNode, asNativeElements, getDebugNode} from './src/deb
 export * from './src/testability/testability';
 export * from './src/change_detection';
 export * from './src/platform_directives_and_pipes';
-export * from './src/platform_common_providers';
-export {APPLICATION_COMMON_PROVIDERS} from './src/application_common_providers';
+export * from './src/platform_core_providers';
+export {APPLICATION_COMMON_PROVIDERS, ApplicationModule} from './src/application_module';
 export {wtfCreateScope, wtfLeave, wtfStartTimeRange, wtfEndTimeRange, WtfScopeFn} from './src/profile/profile';
 
 export {Type} from './src/facade/lang';