SIGNALS:
Here follows a list of supported signals and their meaning; remember
that pmacct core says goodbye when its last child dies or is terminated.


pmacctd/nfacctd/sfacctd Core process:
SIGCHLD:	used to handle gracefully his loved child processes;
SIGHUP:         causes the reopening of connection with syslog daemon;
SIGUSR1:        returns various statistics via either console or syslog; the syslog level reserved
		for such purpose is NOTICE; the facility is selected through configuration (ie key
		'syslog'). It works for all pmacctd/nfacctd/sfacctd;
SIGUSR2:	if 'refresh_maps' configuration directive is enabled it causes the Pre-Tagging map
		to be reloaded; 
SIGINT:		ignored if the daemon is started in background; else the signal is propagated to 
		each running plugin (which is in turn gracefully terminated);
SIGTERM:	not handled (which means it follows the default behaviour for the OS) if the daemon
		is started in background; else it works like SIGINT;
SIGPIPE:	ignored;

MySQL plugin process:
SIGPIPE:	ignored;
SIGCHLD:	ignored;
SIGHUP:		inherited by Core Process; 
SIGUSR1:	ignored;
SIGUSR2:        if 'refresh_maps' configuration directive is enabled it causes the Ports and Networks
		maps to be reloaded;
SIGINT:		causes the process to exit gracefully;	

PGSQL plugin process:
SIGPIPE:	ignored;
SIGCHLD:        ignored; 
SIGHUP:         inherited by Core Process; 
SIGUSR1:	ignored;
SIGUSR2:        if 'refresh_maps' configuration directive is enabled it causes the Ports and Networks
                maps to be reloaded;
SIGINT:         causes the process to exit gracefully;

In-memory table process:
SIGPIPE:        ignored;
SIGCHLD:	ignored; 
SIGHUP:         inherited by Core Process; 
SIGUSR1:	ignored;
SIGUSR2:        if 'refresh_maps' configuration directive is enabled it causes the Ports and Networks
                maps to be reloaded;
SIGINT:         causes the process to exit gracefully;

NetFlow probe process:
SIGPIPE:        ignored;
SIGCHLD:        ignored;
SIGHUP:         inherited by Core Process;
SIGUSR1:        ignored;
SIGUSR2:        if 'refresh_maps' configuration directive is enabled it causes the Ports and Networks
                maps to be reloaded;
SIGINT:         causes the process to exit gracefully;

sFlow probe process:
SIGPIPE:        ignored;
SIGCHLD:        ignored;
SIGHUP:         inherited by Core Process;
SIGUSR1:        ignored;
SIGUSR2:        if 'refresh_maps' configuration directive is enabled it causes the Ports and Networks
                maps to be reloaded;
SIGINT:         causes the process to exit gracefully;