Move IntentSetMultimap to the intent package

As it is no longer resource related

Change-Id: I068bf4bbff33492e3a508c4a4d7a5908a47ee83b
diff --git a/core/api/src/main/java/org/onosproject/net/intent/IntentSetMultimap.java b/core/api/src/main/java/org/onosproject/net/intent/IntentSetMultimap.java
new file mode 100644
index 0000000..dcbad96
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/intent/IntentSetMultimap.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2015-2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.net.intent;
+
+import com.google.common.annotations.Beta;
+
+import java.util.Set;
+
+@Beta
+public interface IntentSetMultimap {
+
+    /**
+     * Allocates the mapping between the given intents.
+     *
+     * @param keyIntentId key intent ID
+     * @param valIntentId value intent ID
+     * @return true if mapping was successful, false otherwise
+     */
+    boolean allocateMapping(IntentId keyIntentId, IntentId valIntentId);
+
+    /**
+     * Returns the set of intents mapped to a lower intent.
+     *
+     * @param intentId intent ID
+     * @return set of intent IDs
+     */
+    Set<IntentId> getMapping(IntentId intentId);
+
+    /**
+     * Releases the mapping of the given intent.
+     *
+     * @param intentId intent ID
+     */
+    void releaseMapping(IntentId intentId);
+}