IDL43 — Allow empty IDL modules

At the moment model generated IDL files are used it could happen that in a certain configuration setting an empty IDL module appears in an IDL file or when doing some prototyping the users uses an empty IDL file. Currently seciton 7.4.1.4.2 of the IDL specification requires an IDL module to have at least 1 definition. We propose to more relax this, to allow an empty IDL module.

Rule 3 should be changed to

<module_dcl> ::= "module" <identifier> "

" A module

And in the text

A list of at least one definition (<definition>+) enclosed within braces ({}). Those definitions form the module body.

Could be changed to

A list of zero or more definitions (<definition>*) enclosed within braces ({}). Those definitions form the module body