Adding support for VLAN_PUSH with EtherType (incl. Q-in-Q)

 - Allowing VLAN_PUSH Instruction to use ethernetType (incl. using REST API)
 - Adding QINQ (0x88a8) Ethernet type
 - Updating InstructionCodec decoders/encoders
 - Updating TrafficTreatment/FlowEntryBuilder

Change-Id: I723cc936a8a49c39da9abe65ba9e5b1bdc1392bf
diff --git a/utils/misc/src/main/java/org/onlab/packet/EthType.java b/utils/misc/src/main/java/org/onlab/packet/EthType.java
index 1519ac0..d2dfec0 100644
--- a/utils/misc/src/main/java/org/onlab/packet/EthType.java
+++ b/utils/misc/src/main/java/org/onlab/packet/EthType.java
@@ -33,6 +33,7 @@
         IPV6(0x86dd, "ipv6", org.onlab.packet.IPv6.deserializer()),
         LLDP(0x88cc, "lldp", org.onlab.packet.LLDP.deserializer()),
         VLAN(0x8100, "vlan", null),
+        QINQ(0x88a8, "qinq", null),
         BDDP(0x8942, "bddp", org.onlab.packet.LLDP.deserializer()),
         MPLS_UNICAST(0x8847, "mpls_unicast", org.onlab.packet.MPLS.deserializer()),
         MPLS_MULTICAST(0x8848, "mpls_unicast", org.onlab.packet.MPLS.deserializer()),