TAJO-665: sort buffer size must be dealt as long type values. (missed casting).
TAJO-659: Add Tajo JDBC documentation.
TAJO-657: Missing table stat in RCFile. (jinho)
TAJO-657: Missing table stat in RCFile. (jinho)
TAJO-659: Add Tajo JDBC documentation.
Merge branch 'branch-0.8.0' of https://git-wip-us.apache.org/repos/asf/incubator-tajo