void usl_set_debug(int debug, void (*log_fn)(int level, const char *fmt, ...))

The application may set a function within the application to handle
debug messages. The level parameter of log_fn is a syslog
log-level. By default, USL dumps debug messages to syslog, unless the
application overrides this variable.

The debug parameter allows the application to turn debug messages
on/off. By default, debugging is on when USL is compiled with -DDEBUG.


