This is part of ongoing work to make core platform-independent.
BREAKING CHANGE
All private exports from 'angular2/src/core/facade/{lang,collection,exception_handler}' should be replaced with 'angular2/src/facade/{lang,collection,exception_handler}'.
These wrappers are not natively understood by
ts2dart. Removing them will improve Dart2JS
compilation due to fewer megamorphic calls to List
functions.
It also makes Angular code more succinct and
improves type safety in Angular due to better type
inference of the Array component type.
This change exposed several bugs in Angular.
