Delta Port Statistics added to DeviceStore, Device Service and CLI
Changed misspelled word in description of the portstats command switch

Change-Id: I131940c83c5cb12080532a4804ec424ca66afa64
diff --git a/core/net/src/main/java/org/onosproject/net/device/impl/DeviceManager.java b/core/net/src/main/java/org/onosproject/net/device/impl/DeviceManager.java
index 6a1724d..83c4a69 100644
--- a/core/net/src/main/java/org/onosproject/net/device/impl/DeviceManager.java
+++ b/core/net/src/main/java/org/onosproject/net/device/impl/DeviceManager.java
@@ -196,6 +196,13 @@
     }
 
     @Override
+    public List<PortStatistics> getPortDeltaStatistics(DeviceId deviceId) {
+        checkPermission(Permission.DEVICE_READ);
+        checkNotNull(deviceId, DEVICE_ID_NULL);
+        return store.getPortDeltaStatistics(deviceId);
+    }
+
+    @Override
     public Port getPort(DeviceId deviceId, PortNumber portNumber) {
         checkPermission(Permission.DEVICE_READ);
         checkNotNull(deviceId, DEVICE_ID_NULL);