fix(ngShow): Add/remove ng-hide class instead of ng-show class

Closes #521
chore(style): code cleanup

fix CS only specify types where strictly necessary
to ease readability.

Closes #522
chore(style): code cleanup
refactor(http): remove a now useless workaround

dartbug.com/13051 has been fixed.
see https://code.google.com/p/dart/issues/detail?id=13051 for details.

Closes #523
feat(ngModel): Treat the values of number and range inputs as numbers

Add a InputNumberLikeDirective that binds the model as a numeric
value, so that it can be bound to num types on scopes. Select the
directive for number and range input types.

Closes #527
test(NgForm): Regression test for #459.

Closes #459
Closes #538
chore(cleanup_todo): Clean-up the TODO sample.
chore(comments): Terminate comment with period.

Closes #539
fix(package.json): add repo, licenses and switch to devDependencies

Fixes #544.
Closes #545
chore(compiler): remove unused, expired code
refactor(forms): remove _NgModelValidator in favor of using a shared interface

_NgModelValidator acted as the base class for validators in AngularDart with earlier
releases. This works, but it poses a problem for custom validators that exist outside
of the AngularDart core. This is because Inheritance is a problem since it is highly
limited when it comes to further refactoring and customization. Interfaces are more
versatile. Therefore all core and custom validators must implement the shared
interface so that they can be attached to ngModel for validation purposes.
chore(documentation-generation): prepare for transition from dartdoc to docgen

Closes #553
chore(test): remove accidental ddescribe
fix(generator): remove invalid sort on elements

cacheUris are sorted later.  sorting the elements can be invalid (e.g.
SimpleStringLiteral has == but no compareTo)

Closes #554
docs(contributing): add developer docs explaining how to setup and run tests

- Create a first version of developer documentation explaining how to
setup and run AngularDart tests locally and on Travis.
- Update `CONTRIBUTING.md` to refer to this new doc.

Closes #322. Assumes #545.

Closes #548
feat(forms): provide support for reseting forms, fieldsets and models
chore(style): clean up indentation.
fix(ng-value): Add ng-value support for checked/radio/option

Closes# 543
fix(doc-gen): dartbug.com/16752