refactor(element binder): Create an ElementBinderBuilder class
fix: Add test to compile examples, fix imports for examples
fix(transformers): fix accidental breakage due to library rename. Added tests.
feat: presubmit now rebuses before it pushes to master
chore: run perf tests as part of build
chore: automatically rebase onto master in presubmit
fix(doc): add angular.core.annotation lib to docs
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.

Closes #842
Adding utility to wrap 'pub build' and generate errors if any new warnings occur.

This is to catch cases where warnings are introduced into the examples but the build does not fail.

Closes #841