add new query resource
Merge branch 'master' of github.com:metamx/druid into query-resource
Merge pull request #304 from metamx/query-resource

Replace query servlet with query resource to make adding new resources easier
prepare for next release
[maven-release-plugin] prepare release druid-0.6.21
[maven-release-plugin] prepare for next development iteration
prepare for next release
[maven-release-plugin] prepare release druid-0.6.22
[maven-release-plugin] prepare for next development iteration
make query resource eagerly instantiate and prepare for next release
[maven-release-plugin] prepare release druid-0.6.23
[maven-release-plugin] prepare for next development iteration