angular/angular.dart — pull request #842 by chalin (2014-04-02 22:57:29+00:00)
Title: refactor(InputCheckboxDirective): fix API doc and refactor ng-true/false-value

- Refactor `NgTrueValue` and `NgFalseValue` so that it smells good!
- Refactor/clean-up InputCheckboxDirective.
- Update `input[type=checkbox]` API doc to reflect AngularDart behavior while following AngularJS-like style.