function getSiblingNode(node) {
	  while (node) {
	    if (node.nextSibling) {
	      return node.nextSibling;
	    }
	    node = node.parentNode;
	  }
	}
Get the next sibling within a container. This will walk up the
DOM if a node's siblings have been exhausted.

@param {DOMElement|DOMTextNode} node
@return {?DOMElement|DOMTextNode}