Fix import node

Fixed bad ordering when adding childs from osgjs files. Now it loads in the same ordering that are defined in the osgjs file. Before it was adding  childs depending on the time to load of each child. I can provide a test.osgjs file. 
forEach is better when we dont care about performance but when you want performance it's better to use this form:
for ( var i = 0, k = jsonObj.Children.length; i < k; i++ ) {
...