fix(node cursor): Do not eat nodes

lib/node_cursor.dart

@@ -95,8 +95,11 @@ class NodeCursor {
     var nodes = nodeList();
 
     for (var i = 0, ii = nodes.length; i < ii; i++) {
-      nodes[i].remove();
+      // NOTE(deboer): If elements is a list of child nodes on a node, then
+      // calling Node.remove() may also remove it from the list.  Thus, we
+      // call elements.removeAt first so only one node is removed.
       elements.removeAt(index);
+      nodes[i].remove();
     }
 
     return new NodeCursor(nodes);

test/node_cursor_spec.dart

@@ -96,6 +96,16 @@ main() {
 
       expect(STRINGIFY(childCursor.elements[0]), equals('<span>text</span>'));
     });
+
+    it('should preserve the top-level elements', () {
+      var dom = $('<span>text</span>MoreText<div>other</div>');
+      var parentCursor = new NodeCursor(dom);
+
+      var childCursor = parentCursor.replaceWithAnchor('child');
+      expect(STRINGIFY(dom), equals('[<!--ANCHOR: child-->, MoreText, <div>other</div>]'));
+
+      expect(STRINGIFY(childCursor.elements[0]), equals('<span>text</span>'));
+    });
   });
 }