Add path stacking

[Fl0pZz]

For example:

{
  name: 'parent',
  url: '/parent',
  children: [
    { name: 'children1', method: 'get', url: 'children1' },  // GET: /parent/children1
    { name: 'children2', method: 'get', url: '/children2' }, // GET: /children1
  ]
}