refactor(Cookies): code cleanup
fix(Cookies): fix for IE and Safari

path should not be null, it would extrapolate to "null"
test(http): disable a flaky expectation

The error message varies across browsers:

    Dartium -> "Unexpected character"
    Dart2JS:
      - Chrome -> "Unexpected token"
      - Firefox -> "unexpected character"
      - IE -> "Invalid character"
refactor(NgEvent): code cleanup
text(NgEvent): fix the mousewheel event on IE
chore(pubspec.yaml): add the browser_detect package
test(ng_form_spec): fix an expectation
test(ng_form_spec): Fix a failing test on IE

ref https://github.com/angular/angular.dart/issues/1309