No functional change.

This fixes #34.

of length fields

The last fix was wrong, so undo it. Only DATA chunk handling was
broken.

This fixes https://github.com/nplab/packetdrill/issues/5.

Please note that packetdrill currently does not support
getsockopt() for non int values.

Using the explicit local IP address instead of the wildcard
address doesn't change the behavior for UDP/TCP, but for
SCTP it forces the SUT to be single homed.

This was a copy and paste error.

This fixes https://github.com/nplab/packetdrill/issues/19

This fixes https://github.com/nplab/packetdrill/issues/18.

When specifying INIT or INIT-ACK chunks allow the tag and the tsn
field to be omitted (meaning tag=... or tsn=... is allowed).