As discussed with @yjbanov, we should deprecate the angular2/angular2 export in Dart since users are encouraged to import angular2/core most often, as well as angular2/bootstrap when defining root components. The angular2/angular2 import is most useful for JavaScript developers who are using the full angular2.js bundle.

I'd originally added this line at the top of angular2.dart as part of #3713, but Dart Analyzer complained about this since some tests and examples were still importing angular2/angular2. So I deferred the change so that I could land the massive PR more quickly.

Here is the deprecation line I originally included at the top of angular2.dart:

@Deprecated('use import angular2/core and angular2/bootstrap instead of angular2')