Make NETGRAPH_DEBUG a kernel option, so that it can't be turned off

without hacking source.

In collaboration with:	ru, julian

sys/conf/NOTES

@@ -501,7 +501,10 @@ options 	ALTQ_DEBUG
 # will automatically load the corresponding KLD module if the node type
 # is not already compiled into the kernel. Each type below has a
 # corresponding man page, e.g., ng_async(8).
-options 	NETGRAPH		#netgraph(4) system
+options		NETGRAPH		# netgraph(4) system
+options		NETGRAPH_DEBUG		# enable extra debugging, this
+					# affects netgraph(4) and nodes
+# Node types
 options 	NETGRAPH_ASYNC
 options 	NETGRAPH_ATMLLC
 options 	NETGRAPH_ATM_ATMPIF

sys/conf/options

@@ -379,6 +379,7 @@ XBONEHACK
 # or loaded dynamically. To get the former, include the corresponding
 # option below. Each type has its own man page, e.g. ng_async(4).
 NETGRAPH
+NETGRAPH_DEBUG		opt_netgraph.h
 NETGRAPH_ASYNC		opt_netgraph.h
 NETGRAPH_ATMLLC		opt_netgraph.h
 NETGRAPH_ATM_ATMPIF	opt_netgraph.h

sys/modules/netgraph/Makefile.inc

@@ -3,4 +3,6 @@
 
 .PATH:		${.CURDIR}/../../../netgraph
 
+SRCS+=	opt_netgraph.h
+
 .include "../Makefile.inc"

sys/netgraph/netgraph.h

@@ -53,8 +53,10 @@
 #include <sys/malloc.h>
 #include <sys/module.h>
 #include <sys/mutex.h>
+
+#include "opt_netgraph.h"
+
 /* debugging options */
-#define NETGRAPH_DEBUG
 #define NG_SEPARATE_MALLOC	/* make modules use their own malloc types */
 
 /*