Add FeaturesReply and its test skeletons.
Merge branch 'develop' into feature/features_reply
Merge branch 'develop' into feature/features_reply
Merge branch 'develop' into feature/features_reply
Add cucumber scenarios of OpenFlow messages.
Rename features/pcap -> features/packet_data and support .raw files.
Merge branch 'develop' into feature/features_reply

Conflicts:
	features/echo_read.feature
	features/features_read.feature
	features/hello_read.feature
	features/step_definitions/pcap_steps.rb
	features/step_definitions/pending_steps.rb
Remove a pending mark from features reply scenario.
Renamed `rake PCAP='foo.pcap' dump_pcap` => `rake PACKET_FILE='foo.pcap' dump`
Add Features Reply parser.
Add minimum Features::Reply.new.
Update changelog.
Add features_request.raw (refs #74).
Merge pull request #68 from trema/feature/features_reply

WIP: FeaturesReply