fix(selector): Allow two directives with the same selector

Fixes #471
Closes #481
style(forms): change currentErrors to errors
chore(pubspec): move unittest into dev_dep
chore(demo): Add simple controller to TodoApp
chore(test): add missing test for ng-change

Closes# 399
fix(eval access): Do not crash on null cached value

Fixes #424
chore(build): More debugging in Travis output
fix(select): Corrected NPE if select multiple nested in ng-if

Closes #428
style(ngModel): change currentErrors to errors
fix(NgComponent): Handle errors while loading CSS

Closes #411
fix(ng-class): array syntax should not insert nulls

Closes #513
fix(ngModel): evaluate user input using onInput instead of onKeyDown
chore(input): Add missing test for clearing input type number

Closes #415
feat(sanitization): make NodeValidator injectable

Closes #490
Closes #498
docs(CONTRIBUTING.md): use run-test.sh instead of grunt

Closes #517
feat(ngRepeat): add track by support

Grab and parse the track by expression if given, and use it to
track the objects.

Closes #277
Closes #507
fix(generator): write files in sorted order for predictable tests
fix(forms): ensure fields, fieldsets & forms are marked as dirty when modified