feat(NgAnnotations): allow ignoring child nodes during compilation

BREAKING CHANGE:
- `NgDirective` loses `transclude`.  Transclusion is indicated by setting
  the `children` string enum to `NgAnnotationBase.TRANSCLUDE_CHILDREN`.
- `NgNonBindableDirective` / `ng-non-bindable` suppressing compilation only
  on the child nodes but does not prevent processing other directives or
  interpolations on the same node.