Only symlink booted kernel directory to /boot/kernel if user has explicitly

requested it.  This is too dangerous to just do behind the admin's back.

etc/defaults/rc.conf

@@ -542,6 +542,7 @@ sysvipc_enable="NO"	# Load System V IPC primitives at startup (or NO).
 linux_enable="NO"	# Linux binary compatibility loaded at startup (or NO).
 svr4_enable="NO"	# SysVR4 emulation loaded at startup (or NO).
 
+kernel_enable="NO"	# Symlink kernel directory to /boot/kernel if not exist.
 clear_tmp_enable="NO"	# Clear /tmp at startup.
 clear_tmp_X="YES" 	# Clear and recreate X11-related directories in /tmp
 ldconfig_insecure="NO"	# Set to YES to disable ldconfig security checks

etc/rc.d/kernel

@@ -10,6 +10,7 @@
 . /etc/rc.subr
 
 name="kernel"
+rcvar=`set_rcvar`
 start_cmd="kernel_start"
 stop_cmd=":"