The worker now gets the bytes-in/bytes-out for the specified
protocol (http or tcp). For now, these values are only logged,
and then only in debug mode. Added a test for setting these
values in the new LBStatistics class.
Updated README for the 'socat' requirement and to mention that
the PID file directory must be writable by the user.
Change-Id: I79f218747255cba84b25c4a69d0b210c9d1dfee5