Add callback manager

Callback manager sets up matches and sets properties on
dbus.

Tested: used sensor override to make sensors assert
critical and warning interfaces and saw led change. also
caught a few buggy threshold settings using led.

Change-Id: I06c164b749febbc3e81cb3db5f7a0a2b72b3678f
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/callback-manager/service_files/callback-manager.service b/callback-manager/service_files/callback-manager.service
new file mode 100644
index 0000000..b6abae3
--- /dev/null
+++ b/callback-manager/service_files/callback-manager.service
@@ -0,0 +1,13 @@
+[Unit]
+Description=Callback Manager
+StopWhenUnneeded=false
+
+[Service]
+Type=dbus
+BusName=xyz.openbmc_project.CallbackManager
+Restart=always
+RestartSec=5
+ExecStart=/usr/sbin/callback-manager
+
+[Install]
+WantedBy=multi-user.target