EXT-112: Introduce new OXM field OXM_OF_PACKET_TYPE.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
EXT-112: Test for OXM_OF_PACKET_TYPE.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
EXT-112: Reject packet-out with non-Ethernet packet-type.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
EXT-112: Pretty-print packet-type.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>