Fix encoding of ofp_table_features with zero-length name

If the name field in the record is empty, the name field in the message
would occupy 0 bytes instead of 32.  This change ensures that we use the
proper field length in all cases.
Add support for connections initiated by OF controllers

OpenFLow 1.3.2 specification introduces a new statement that OpenFlow
controllers can connect to OpenFlow switches. For the time being
we support only TCP connections from controller. In the future the switch
should only support secure connection as specification recommends.
(FlowForwarding/LINC-Switch#147).
Adjust ofp_client, ofp_channel to accepting established connection

OpenFLow 1.3.2 specification introduces a new statement that OpenFlow
controllers can connect to OpenFlow switches. ofp_client and ofp_channel
along with tests had to be refactored to support this new functionality
by accepting a socket with already established connection from
the controller.
(FlowForwarding/LINC-Switch#147).
Merge pull request #49 from FlowForwarding/issue147

Add support for connections initiated by OF controllers
Add .travis.yml file, for compiling on Travis CI
Specify Erlang/OTP release to use on Travis CI

Our included rebar binary is too new to run on the default Erlang/OTP
version in use at Travis CI.  Let's specify a few recent releases to
use.
fix the value of multipart "more" flag
Merge pull request #51 from yamt/multipart-fix

fix the value of multipart "more" flag
remove unused ofp_action_set_queue.port
Merge pull request #52 from yamt/queue-port

remove unused ofp_action_set_queue.port
Merge pull request #47 from legoscia/table_features_encoding

Fix encoding of ofp_table_features with zero-length name
Add OFPVID_PRESENT and OFPVID_NONE values for matching on VLAN tags

These values are used to indicate special conditions in matching
VLAN tagged frames.
(Motivated by FlowForwarding#134).
Change meck dependency to tag 0.8.1

Crucially, this removes a test for parameterised modules, which are no
longer supported in R16.
Merge pull request #55 from FlowForwarding/issue134

Add OFPVID_PRESENT and OFPVID_NONE values for matching on VLAN tags
Merge pull request #54 from legoscia/use-meck-0.8.1

Change meck dependency to tag 0.8.1
Merge pull request #53 from legoscia/use-travis

Add configuration file for Travis CI