TAJO-1174: remove unnessary codes for blobdatum (DaeMyung Kang via hyunsik)
TAJO-1179: Integration tests in TravisCI are occasionally failed due to log size.

Closes #245
TAJO-1169: Some older version of OpenJDK 1.6 does not get default timezone id. (Jihun Kang via hyunsik)

Closes #239
Merge branch 'master' of http://git-wip-us.apache.org/repos/asf/tajo into index_support