basic-1.3: add OutputWildcard and PacketInWildcard tests

These tests check that a match-all (but not table-miss) flow matches packets.
initial OpenFlow 1.3 match tests

The only tests currently implemented are for the VLAN tag.
do not attempt to execute base tests

The OF 1.3 match.MatchTest class was intended to just be a base class, but
since it inherits from unittest.TestCase it was being run as a test.

This change ignores test classes that don't include a runTest field.
match-1.3: add tests for masked vlan VID/PCP

Masking vlan PCP is not required by OpenFlow, but switches are allowed to
implement it.
match-1.3: ethernet src/dst
match-1.3: add ethertype tests
match-1.3: add IPv4 dscp/ecn tests
match-1.3: add ipv4 proto tests
match-1.3: add ipv4 tcp/udp src/dst tests
match-1.3: add ipv4 src/dst tests
match-1.3: add ipv4 icmp type/code tests
match-1.3: add arp operation test
match-1.3: add arp sender/target tests
match-1.3: add in_port test
testutils: add simple_{tcp,udp,icmp}v6_packet()

These are simplified and IPv6-ified versions of the existing functions.

Also added IPv6 packets to the OF 1.3 ethertype tests.
match-1.3: add IPv6 dscp/ecn tests
match-1.3: add IPv6 proto tests
match-1.3: add IPv6 icmp type/code tests
match-1.3: add IPv6 tcp/udp src/dst port tests
match-1.3: add IPv6 src/dst tests