DIST_QUERY_CLUSTER_SLOT_MAX_RATIO bug fix
Merge branch 'SKT-2014-08-07' of https://github.com/gruter/incubator-tajo_g into skt-scheduler-0807
Merge branch 'skt-scheduler-0807' of https://github.com/gruter/incubator-tajo_g into skt-scheduler-0807
fixed DIST_QUERY_CLUSTER_SLOT_MAX_RATIO in groupby