Log to stderr based on log level

Description:

These flags indicate that an attempt should be made to output log messages with the specified log level to stderr. This action is often required when a process does something that should not go unnoticed at startup (e.g., it exits because of a critical error) and it is useful to output a log message to stderr. Only the critical, shutdown, error, and warning levels are provided because all other levels are typically not important enough to require a message to go to stderr specifically.

Definitions:

#define QH_LOG_SHUTDOWN_STDERR 

#define QH_LOG_CRITICAL_STDERR 

#define QH_LOG_ERROR_STDERR 

#define QH_LOG_WARNING_STDERR