2004-11-23 Andrew J. Schorr <ajschorr@alumni.princeton.edu>

2004-11-23 Andrew J. Schorr <ajschorr@alumni.princeton.edu>

	* sigevent.c: (signal_init) Set up some default signal handlers
	  so that processes will issue an error message before terminating
	  or dumping core.
	  (trap_default_signals) New function to set up signal handlers
	  for various signals that may kill the process.
	  (exit_handler) Call zlog_signal, then _exit.
	  (core_handler) Call zlog_signal, then abort.
	* log.h: Declare new function zlog_signal.
	* log.c: (zlog_signal) New function to log information about
	  a received signal before the process dies.  Try to log a
	  backtrace also.
	  (quagga_signal_handler,signal_set) Should be static.