Add rc-sstat script

The rc-sstat script is written to display status of s6 services and
run rc-status to display all services status.

This currently only works on Linux.

man/Makefile

@@ -1,9 +1,17 @@
+MK=		../mk
+include ${MK}/sys.mk
+include ${MK}/os.mk
+
 MAN3=		einfo.3 \
 		rc_config.3 rc_deptree.3 rc_find_pids.3 rc_plugin_hook.3 \
 		rc_runlevel.3 rc_service.3 rc_stringlist.3
 MAN8=		rc-service.8 rc-status.8 rc-update.8 openrc.8 openrc-run.8 \
 		service.8 start-stop-daemon.8
 
+ifeq (${OS},Linux)
+MAN8 += rc-sstat.8
+endif
+
 # Handy macro to create symlinks
 # This does rely on correctly formatting our manpages!
 MAKE_LINKS=	suffix=$${man\#*.}; \
@@ -16,8 +24,6 @@ MAKE_LINKS=	suffix=$${man\#*.}; \
 		fi; \
 		done;
 
-MK=		../mk
-include ${MK}/sys.mk
 include ${MK}/gitignore.mk
 
 all: