SimpleLinkStore with annotation and multi-provider support

Change-Id: I98a35c4497363c6115fd0c61d140dfe7790e6cee
diff --git a/core/api/src/main/java/org/onlab/onos/net/link/LinkDescription.java b/core/api/src/main/java/org/onlab/onos/net/link/LinkDescription.java
index b1be82c..4b34ad6 100644
--- a/core/api/src/main/java/org/onlab/onos/net/link/LinkDescription.java
+++ b/core/api/src/main/java/org/onlab/onos/net/link/LinkDescription.java
@@ -1,12 +1,13 @@
 package org.onlab.onos.net.link;
 
 import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.Description;
 import org.onlab.onos.net.Link;
 
 /**
  * Describes an infrastructure link.
  */
-public interface LinkDescription {
+public interface LinkDescription extends Description {
 
     /**
      * Returns the link source.