Fix missing/misplaced '#include "config.h"' statements. Fixes missing
function prototypes, unknown type definitions, etc. Allows configuration
of GCC with CFLAGS="-std=c23" instead of using default -std=gnu23.
Don't know about CLANG, MSVC, MinGW, etc, but using
gwb@stitch:~> gcc --version
gcc (SUSE Linux) 15.1.1 20250714
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This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Hamlib can compile in strict C23 mode, or previous standard levels.