Steps to reproduce

I believe I found out what causes #670

1. Create a route e.g. /organizations
2. Create a nested route e.g /organizations/:orgId/people
3. Perform a REST call to /organizations, /organizations/xyz, /organizations/xyz/people everything works fine
4. Perform a Socket call to /organizations/xyz/people - the request goes to /organizations/xyz and not /organizations/xyz/people

In the radix-router, function _findNode(path, rootNode) loops through all the nodes in the router. In the above, the nodes tree looks like so:

+-- organization
|----+-- :__id
|----+-- :orgId
|--------+-- people

When doing a lookup, /organizations/xyz/people, radix matches the __id node (even though it should match :orgId/people

Expected behavior

The router should match the :orgId/people node and not the :__id node

Solutions

Create the following routes instead:

/organizations
/organizations/:__id/people

which creates a proper node tree within radix:
+-- organization
|---+-- :__id
|-------+-- people

The danger here is that :__id is undocumented and may change in the future. Is this ok? The above does not affect the REST transport, just socketio.