Stub out $scope.$parent recursively; dom.element enhancements;

- $scope.$parent is now stubbed recursively in case you need to stub properties on it (even .$parent.$parent). Without breaking the connection to the duck $rootScope, your stubs are merged with the real duck $parent.
- You can now pass a dom.element into interactWith (in addition to the already support css selector string). This is good if you've already stored a reference to your element into a variable. e.g. `dom.interactWith(someButtonReference);`
- You can now interact with any non-input object as long as it has an ng-click attribute. e.g. `dom.interactWith(someDivWithNgClick);`
- dom.element objects now have isRemoved() to see if they are still connected to the duck dom. Sometimes when items are added and removed (e.g. with ng-if) they still exist in memory but are not in the dom. 
- dom.element now extends the .find method so you can search for descendant elements of a dom.element object and it will return another dom.element element. Previously it returned a regular jquery element, so you could access the various dom.element helpers like isHidden, isVisible, etc. e.g. `dom.element(".someDiv").find(".someChildDiv");` now returns a dom.element object.