Configure whether the built-in log functions
(g_log_default_handler() for the old-style API, and both
g_log_writer_standard_streams() for the
structured API) will output all log messages to
By default, log messages of levels
G_LOG_LEVEL_DEBUG are sent to
stdout, and other log messages are
stderr. This is problematic for applications that intend
stdout for structured output such as JSON or XML.
This function sets global state. It is not thread-aware, and should be called at the very start of a program, before creating any other threads or creating objects that could create worker threads of their own.