finish implementing lumberjack protocol in lumberjack2 (test works against logstash 1.1.13)
finish implementing lumberjack protocol in lumberjack2 (test works
against logstash 1.1.13)

This has one slight behavioral change from the C version. We now
send a window size change before every spooled payload. This has
the effect of allowing slow publishers to be acknowledged sooner.

linearregression/log-courier,MichaelLiZhou/log-courier,srizzling/log-courier,MichaelLiZhou/log-courier,scrapinghub/log-courier,dixitk13/log-courier,linearregression/log-courier,dixitk13/log-courier,scrapinghub/log-courier,srizzling/log-courier,scrapinghub/log-courier,MichaelLiZhou/log-courier,dixitk13/log-courier,srizzling/log-courier,linearregression/log-courier