Added Change utility class for representing change events + Moved Match class to org.onlab.util

Change-Id: I08e8cd8dd92983bd2764e83016b1abc0bf29388f
diff --git a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultDatabaseState.java b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultDatabaseState.java
index 8943fc8..3bb413c 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultDatabaseState.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultDatabaseState.java
@@ -21,8 +21,11 @@
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
+
 import net.kuujo.copycat.state.Initializer;
 import net.kuujo.copycat.state.StateContext;
+
+import org.onlab.util.Match;
 import org.onosproject.store.service.DatabaseUpdate;
 import org.onosproject.store.service.Transaction;
 import org.onosproject.store.service.Versioned;