9696 add /etc/system.d support
Portions contributed by: Andy Fiddaman <andy@omniosce.org>
Reviewed by: Hans Rosenfeld <hans.rosenfeld@joyent.com>
Reviewed by: Peter Tribble <peter.tribble@gmail.com>
Reviewed by: C Fraire <cfraire@me.com>
Reviewed by: Toomas Soome <tsoome@me.com>

@@ -14,10 +14,11 @@
 etc/name_to_major
 etc/name_to_sysnum
 etc/path_to_inst
 etc/rtc_config
 etc/system
+etc/system.d
 etc/hostid
 kernel
 platform/i86hvm/kernel
 platform/i86pc/kernel
 platform/i86xpv/kernel