treewide: Cleanup signal emission

Don't emit properties changed prior to interfaces added.

Change-Id: I7f88b8052a323ca49ce9f16fe446596213e3fdb5
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/neighbor.cpp b/src/neighbor.cpp
index 0f5140e..6b8d853 100644
--- a/src/neighbor.cpp
+++ b/src/neighbor.cpp
@@ -34,11 +34,9 @@
     NeighborObj(bus, objPath.str.c_str(), NeighborObj::action::defer_emit),
     parent(parent), objPath(std::move(objPath))
 {
-    NeighborObj::ipAddress(std::to_string(addr));
-    NeighborObj::macAddress(std::to_string(lladdr));
-    NeighborObj::state(state);
-
-    // Emit deferred signal.
+    NeighborObj::ipAddress(std::to_string(addr), true);
+    NeighborObj::macAddress(std::to_string(lladdr), true);
+    NeighborObj::state(state, true);
     emit_object_added();
 }