TAJO-1028: JDBC should support SET command.

Closes #135
TAJO-1029: TAJO_PULLSERVER_STANDALONE should be false in default tajo-env.sh. (jinho)

Closes #134
TAJO-1022: tsql does not work as background process

Closes #128
TAJO-1027: Upgrade Hive to 0.13.0 and 0.13.1. (jaehwa)
TAJO-1010: Improve multiple DISTINCT aggregation.
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/tajo into TAJO-1010