Replace old CMake scripts with defgen.py and symgen.py
Add "void" in empty argument lists

In C, an empty argument list means you can pass any number of
arguments to the function, whereas (void) means no arguments.
Rename timer-linux.c to timer-posix.c
Rename plugin-linux.c to plugin-glibc.c
Remove _GNU_SOURCE anti-redefinition check
Port fakeamx to DEFINE_INIT_FUNC / DEFINE_CLEANUP_FUNC
Make do_log() default to printf when logprintf is not initialized
Add log_error_code()