Added simple link manager implementation.
Added link admin stuff; unit tests to come.
diff --git a/net/api/src/main/java/org/onlab/onos/net/link/LinkDescription.java b/net/api/src/main/java/org/onlab/onos/net/link/LinkDescription.java
index 83af07c..b1be82c 100644
--- a/net/api/src/main/java/org/onlab/onos/net/link/LinkDescription.java
+++ b/net/api/src/main/java/org/onlab/onos/net/link/LinkDescription.java
@@ -1,6 +1,7 @@
 package org.onlab.onos.net.link;
 
 import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.Link;
 
 /**
  * Describes an infrastructure link.
@@ -21,5 +22,13 @@
      */
     ConnectPoint dst();
 
+    /**
+     * Returns the link type.
+     *
+     * @return link type
+     */
+    Link.Type type();
+
+
     // Add further link attributes
 }