TAJO-1161: Remove joda time dependency from tajo-core. (Jihun Kang via hyunsik)

Closes #233
TAJO-1109: Separate SQL Statements from Catalog Stores. (Jihun Kang via hyunsik)

Closes #201
TAJO-1152: RawFile ByteBuffer should be reuse. (jinho)

Closes #224
TAJO-1151: Implement the ByteBuffer-based De/Serializer. (jinho)

Closes #228
TAJO-1156: Improve the comparison of timestamp and date types. (Jihun Kang via jihoon)

Closes #237
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