Added simple link manager implementation.
Added link admin stuff; unit tests to come.
diff --git a/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleLinkManager.java b/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleLinkManager.java
index 1c7306f..63fb2cc 100644
--- a/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleLinkManager.java
+++ b/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleLinkManager.java
@@ -50,7 +50,7 @@
     private final SimpleLinkStore store = new SimpleLinkStore();
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    private EventDeliveryService eventDispatcher;
+    protected EventDeliveryService eventDispatcher;
 
     @Activate
     public void activate() {