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
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/tajo into index_support

Conflicts:
	tajo-catalog/tajo-catalog-server/src/main/resources/schemas/derby/indexes.sql
index support
Merge branch 'index_support' of https://git-wip-us.apache.org/repos/asf/tajo into TAJO-838_3

Conflicts:
	tajo-catalog/tajo-catalog-server/src/main/java/org/apache/tajo/catalog/store/DerbyStore.java
	tajo-catalog/tajo-catalog-server/src/main/resources/schemas/derby/indexes.sql
	tajo-catalog/tajo-catalog-server/src/main/resources/schemas/postgresql/indexes.sql