CORBA3 — Type code creation

The core spec says in section 4.11.3:

Typecode creation operations that take name as an argument shall check that
the name
is a valid IDL name or is a null string.

This is oxymoronic: we are talking about IDL here; IDL does not have the
concept of
a null string. If anything, we can say "empty string".

Looking at this bit of spec, it would appear that a call such as

orb->create_interface_tc(someRepId, 0);

is legal. But that doesn't make sense because it's illegal to pass null
pointers
across IDL interfaces in C++ (or null references as strings in Java).

Fix as suggested