This commit consists of adding two new northbound APIs to the Core
to be used mostly by the Affinity Router: ListDeviceIds retrieves the
ids of devices present in a Core memory; ReconcileDevices ia an API
the Affinity router can use to push a list of device ids to a Core
for the latter to load and reconcile the devices in memory (used
mostly of a core restart).

Change-Id: I0d292054e09a099ad8be7669fbc3fe3ba15a5579
diff --git a/protos/common.proto b/protos/common.proto
index d1234d5..b1c13ae 100644
--- a/protos/common.proto
+++ b/protos/common.proto
@@ -11,6 +11,11 @@
     string id = 1;
 }
 
+// Represents a list of IDs
+message IDs {
+    repeated ID items = 1;
+}
+
 enum TestModeKeys {
     api_test=0;
 }