sw test tool: FIX: permit the order different of lists in the case of comparison

some switches return the instruction list of flow_mod messages in the different order.

for example, when a flow entry was installed with the instructions as:

  [
    OFPInstructionMeter(meter_id=1),
    OFPInstructionActions(actions=[OFPActionOutput(port=2)])
  ]

the flow_stats message may return the flow entry with the instructions as:

  [
    OFPInstructionActions(actions=[OFPActionOutput(port=2)]),
    OFPInstructionMeter(meter_id=1)
  ]

this patch makes tester.py ignore the order different.

Signed-off-by: Yuichi Ito <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>