[swarm_ctrl] No need to do both chunks in log_stats callback.

This information is already included in the baselines looop.
[swarm_ctrl] Added an argparse option to log or not log stats.
[swarm/core] Some fixes to how the QDR verification is done.
[swarm/core] Changed set_itime to use non-hard-coded Walsh step length.
[swarm/defines] Changed Walsh step length from 64 to 128.

This is only appropriate for the half-rate system using all 16 inputs
and the SMA 256-step Walsh patterns (of which we only use the even
ones).
[swarm/core] Extracted the sync part of Swarm.setup into Swarm.sync.

This should allow re-syncing after an initial setup though this may not
be used since it may upset a running system.
[swarm/core] Added the ability to load de-Walsh patterns.

This reads a pre-computed file of antenna to Walsh pattern mapping and
writes the patterns into the block memory on the FPGA responsible for
de-Walshing. There is a function to do this in SwarmMember and another
to run this function in a Swarm for all members.
[swarm/data] The received accumulation log messages are now INFO level.
[swarm] Added a simple setuptools setup script.

Recommended usage is as folows:

$ python setup.py develop

This points python to the repository (instead of installing it to the
Python install path) so that changes can be made without needed to re-run
the installation.