CORBA24 — POA namespace and ORB ID

Section 4.6 of CORBA 2.3.1 addresses the meaning of the ORBid argument. It is clear
that ORB_init can be called multiple times in the same address space resulting in
different ORBs. I think the CORBA spec should make it clear that all of these ORBs
have different POA namespaces. This should probably be indicated in section 11.2.3
by stating something like:

If an application makes use of multiple ORBs in the same address space, each
ORB defines its own separate POA namespace. In particular, each ORB returns a
distinct root POA in response to a resolve_initial_references( "RootPOA" )
call.

Clarifying sentence is justified.