[CLN-list] CLN switched to C++11

[Bruno Haible]

I wrote:
> As standards evolve in big steps, and compiler support evolves in small
> steps, it is normal that a compiler supports only a portion of the
> language feature of every standard.

More details about this here:
https://en.cppreference.com/w/cpp/compiler_support

You can see from the C++11 table that MSVC 14 (here denoted as 19.0)
supports 39 out of 43 C++11 features.

Bruno