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.