CORD-613 Adding ability to administratively enable or disable a port via CLI.
Currently uses the OpenFlow device provider to change portState.
Also fixes a bug in PortNumberCompleter.
Adds completion options to portstats for deviceId and portNumber.

Change-Id: Idcce775fe8bc5484fdd0e630bcb5026b85125478
diff --git a/core/api/src/main/java/org/onosproject/net/device/DeviceAdminService.java b/core/api/src/main/java/org/onosproject/net/device/DeviceAdminService.java
index 500b635..a750e06 100644
--- a/core/api/src/main/java/org/onosproject/net/device/DeviceAdminService.java
+++ b/core/api/src/main/java/org/onosproject/net/device/DeviceAdminService.java
@@ -16,6 +16,7 @@
 package org.onosproject.net.device;
 
 import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
 
 /**
  * Service for administering the inventory of infrastructure devices.
@@ -31,4 +32,13 @@
 
     // TODO: add ability to administratively suspend/resume device
 
+
+  /**
+   * Administratively enables or disables a port on a device.
+   *
+   * @param deviceId  device identifier
+   * @param portNumber port identifier
+   * @param enable true if port is to be enabled, false to disable
+   */
+    void changePortState(DeviceId deviceId, PortNumber portNumber, boolean enable);
 }