Make lcm-logger flush buffers before exiting
Make lcm-logger flush buffers before exiting

Make the write thread of lcm-logger write out all messages remaining in
the queue before exiting. This means that messages received by
lcm-logger before the lcm-logger was asked to terminate end up in the
log.

This fixes lcm-proj/lcm#173.

bluesquall/lcm,bluesquall/lcm,lcm-proj/lcm,lcm-proj/lcm,lcm-proj/lcm,bluesquall/lcm,lcm-proj/lcm,lcm-proj/lcm,bluesquall/lcm,lcm-proj/lcm,bluesquall/lcm,bluesquall/lcm,lcm-proj/lcm,bluesquall/lcm,lcm-proj/lcm