[omniORB] OmniOrb and C++17 support

[Daniel Krügler]

Beginning with C++17, dynamic exception specifications have been
removed from the C++ language. This means it is not possible to use
OmniOrb in a program that us build using a C++17 compiler.

Would it be possible to provide a 4.2.4 release version of OmniOrb
that can be compiled against C++17?

Assuming that the current 4.3.x development branch does already
support C++17, when is the first 4.3 release planned?

Thanks,

- Daniel