IPSEC: SPD counters in the stats sgement

- return the stats_index of each SPD in the create API call
- no ip_any in the API as this creates 2 SPD entries. client must add both v4 and v6 explicitly
- only one pool of SPD entries (rhter than one per-SPD) to support this
- no packets/bytes in the dump API. Polling the stats segment is much more efficient
  (if the SA lifetime is based on packet/bytes)
- emit the policy index in the packet trace and CLI commands.

Change-Id: I7eaf52c9d0495fa24450facf55229941279b8569
Signed-off-by: Neale Ranns <nranns@cisco.com>

test/template_ipsec.py

@@ -380,6 +380,11 @@ class IpsecTun4Tests(object):
             self.logger.info(self.vapi.ppcli("show error"))
             self.logger.info(self.vapi.ppcli("show ipsec"))
 
+        if (hasattr(p, "spd_policy_in_any")):
+            pkts = p.spd_policy_in_any.get_stats()['packets']
+            self.assertEqual(pkts, count,
+                             "incorrect SPD any policy: expected %d != %d" %
+                             (count, pkts))
         self.assert_packet_counter_equal(self.tun4_encrypt_node_name, count)
         self.assert_packet_counter_equal(self.tun4_decrypt_node_name, count)