C Craft

Some notes on the "Opt-in visibility" part, which is a bit minimal:

- This requires a shared lib, it doesn't work with static libs.

- Various descriptions online imply that you need a C++ compiler or use of C++ for this to work (for example the official gcc docs, https://gcc.gnu.org/wiki/Visibility, refer to it as "C++ visibility support"), but it works just as well with plain C.

- The option is available for both kinds, country and west... ah, clang and gcc.