* cache file sync before making updates to Dart jade * app.module.ts: fix ngmodule docregion * [TS] dependency-injection.jade updates * [Dart] dependency-injection.jade updates * final ts/_cache file sync
Fixes #2493 No need to dual boot `AppComponent` and `ProvidersComponent` only to ensure that we could demo optional injection; instead just inject null for the `@Optional` constructor parameter type. No prose is affected by these changes.
