groups-1.3: add tests for SELECT group forwarding

Tests empty, single-buckets, and multiple-bucket groups.

Does not test port-down or unequal-weight scenarios. Doesn't use any bucket
actions other than a single output.
Merge into master from pull request #77:
update pyloxi (https://github.com/floodlight/oftest/pull/77)
add bsn_in_ports test

This tests the BSN extension OXM that enables the controller to specify a
bitmap of allowed input ports. See the loxigen bsn_in_ports input file for more
details.
Merge into master from pull request #78:
add bsn_in_ports test (https://github.com/floodlight/oftest/pull/78)
Merge into master from pull request #76:
groups-1.3: add tests for SELECT group forwarding (https://github.com/floodlight/oftest/pull/76)
add pktin_match test module

This tests the match sent in OF 1.3 packet-in messages. Only the VLAN VID OXM
is covered at the moment.
Merge into master from pull request #79:
add pktin_match test module (https://github.com/floodlight/oftest/pull/79)
When handling OF messages from switch, use matching OF version.
Merge into master from pull request #80:
When handling OF messages from switch, use matching OF version. (https://github.com/floodlight/oftest/pull/80)
Allow table_id override from --test-params.
Remove unneeded util function.
Merge into master from pull request #81:
Allow table_id override from --test-params. (https://github.com/floodlight/oftest/pull/81)
update pyloxi to c4da04db638135e618763773bd03371db1c9b7fd