add more meaningful request logging
address code review comments
fix another missing log
Merge pull request #475 from metamx/better-request-logs

Add more meaningful request logging
[maven-release-plugin] prepare release druid-0.6.87
[maven-release-plugin] prepare for next development iteration
actually emit query stats
[maven-release-plugin] prepare release druid-0.6.88
[maven-release-plugin] prepare for next development iteration