CORBA25 — #include issue

A minor issue with section 3.3 of the 2.4 specification:

"... Text in files included with a #include directive is treated as
if it appeared in the including file. ..."

That is not true since, as we find out in chapter 10, included files
behave specially with regard to assigning repository identifiers.

e.g. in

// a.idl
#pragma prefix "foo"
interface bar {};

the repository id of bar is IDL:foo/bar:1.0, but in

// a.idl
#pragma prefix "foo"
#include "b.idl"

// b.idl
interface bar {};

it is just IDL:bar:1.0.

Incorporate changes and close issue