Moved generic Timestamp/ClockManager classes to onos-api
so they are usable by applications.

Change-Id: Icf0e92d12434dec782332e91b632da8066a85b60
diff --git a/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java b/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java
index 8a31de1..60b72d7 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java
@@ -62,7 +62,7 @@
 import org.onosproject.store.cluster.messaging.ClusterCommunicationService;
 import org.onosproject.store.cluster.messaging.ClusterMessage;
 import org.onosproject.store.cluster.messaging.ClusterMessageHandler;
-import org.onosproject.store.impl.MultiValuedTimestamp;
+import org.onosproject.store.service.MultiValuedTimestamp;
 import org.onosproject.store.serializers.KryoNamespaces;
 import org.onosproject.store.service.ClockService;
 import org.onosproject.store.service.EventuallyConsistentMap;