function toChildrenFirstArray(aTree) {
		var aChildrenFirst = [];
		function addToLeafsFirst(node) {
			if (node.nodes) {
				node.nodes.forEach(function(child) {
					addToLeafsFirst(child);
				});
			}
			aChildrenFirst.push(node);
		}
		aTree.forEach(function(parent) {
			addToLeafsFirst(parent);
		});
		return aChildrenFirst;
	}
Creates an array of all tree nodes,
where the child nodes precede the parent nodes
@param aTree
@returns {Array}