Remove custom org.openbmc.Object.ObjectMapper

Use the standard freedesktop ObjectManager interface.

Moved gdbus OM export calls to the correct place so these
signals are emitted as expected by system_manager.py.
Python apps that use pyobmc are already emitting these
correctly.

Change system_manager.py to watch for the freedesktop
signal rather than the custom one.

Added an sd_bus OM to led_controller.
diff --git a/Makefile b/Makefile
index 8a88a37..7129082 100755
--- a/Makefile
+++ b/Makefile
@@ -35,27 +35,27 @@
 libopenbmc_intf: openbmc_intf.o
 	$(CC) -shared -o lib/$@.so obj/openbmc_intf.o $(LDFLAGS)
 
-power_control: power_control_obj.o gpio.o object_mapper.o libopenbmc_intf
-	$(CC) -o bin/$@.exe obj/gpio.o obj/power_control_obj.o obj/object_mapper.o $(LDFLAGS) $(LIBS)
+power_control: power_control_obj.o gpio.o libopenbmc_intf
+	$(CC) -o bin/$@.exe obj/gpio.o obj/power_control_obj.o $(LDFLAGS) $(LIBS)
 
 led_controller: led_controller.o
 	$(CC) -o bin/$@.exe obj/led_controller.o $(LDFLAGS) $(LIB_FLAG)
 
-button_power: button_power_obj.o gpio.o object_mapper.o libopenbmc_intf
-	$(CC) -o bin/$@.exe obj/button_power_obj.o obj/gpio.o obj/object_mapper.o $(LDFLAGS) $(LIBS)
+button_power: button_power_obj.o gpio.o libopenbmc_intf
+	$(CC) -o bin/$@.exe obj/button_power_obj.o obj/gpio.o $(LDFLAGS) $(LIBS)
 
-button_reset: button_reset_obj.o gpio.o object_mapper.o libopenbmc_intf
-	$(CC) -o bin/$@.exe obj/button_reset_obj.o obj/gpio.o obj/object_mapper.o $(LDFLAGS) $(LIBS)
+button_reset: button_reset_obj.o gpio.o libopenbmc_intf
+	$(CC) -o bin/$@.exe obj/button_reset_obj.o obj/gpio.o $(LDFLAGS) $(LIBS)
 
 
-control_host: control_host_obj.o gpio.o object_mapper.o libopenbmc_intf
-	$(CC) -o bin/$@.exe obj/gpio.o obj/control_host_obj.o obj/object_mapper.o $(LDFLAGS) $(LIBS)
+control_host: control_host_obj.o gpio.o libopenbmc_intf
+	$(CC) -o bin/$@.exe obj/gpio.o obj/control_host_obj.o $(LDFLAGS) $(LIBS)
 
-flash_bios:  flash_bios_obj.o object_mapper.o libopenbmc_intf
-	$(CC) -o bin/$@.exe obj/flash_bios_obj.o obj/object_mapper.o $(LDFLAGS) $(LIBS)
+flash_bios:  flash_bios_obj.o libopenbmc_intf
+	$(CC) -o bin/$@.exe obj/flash_bios_obj.o $(LDFLAGS) $(LIBS)
 
-host_watchdog: host_watchdog_obj.o object_mapper.o libopenbmc_intf
-	$(CC) -o bin/$@.exe obj/host_watchdog_obj.o obj/object_mapper.o  $(LDFLAGS) $(LIBS)
+host_watchdog: host_watchdog_obj.o libopenbmc_intf
+	$(CC) -o bin/$@.exe obj/host_watchdog_obj.o $(LDFLAGS) $(LIBS)
 
 board_vpd: board_vpd_obj.o libopenbmc_intf
 	$(CC) -o bin/$@.exe obj/board_vpd_obj.o $(LDFLAGS) $(LIBS)
@@ -69,8 +69,8 @@
 pflash:  $(OBJS2) pflash.o
 	$(CC) -o bin/$@ obj/pflash.o $(OBJS3) $(LDFLAGS)
 
-hwmons_barreleye: hwmons_barreleye.o object_mapper.o libopenbmc_intf
-	$(CC) -o bin/$@.exe obj/hwmons_barreleye.o obj/object_mapper.o  $(LDFLAGS) $(LIBS)
+hwmons_barreleye: hwmons_barreleye.o libopenbmc_intf
+	$(CC) -o bin/$@.exe obj/hwmons_barreleye.o $(LDFLAGS) $(LIBS)
 
 control_bmc: control_bmc_obj.o libopenbmc_intf
 	$(CC) -o bin/$@.exe obj/control_bmc_obj.o $(LDFLAGS) $(LIBS)