Limit the Protocol Buffers to use 2.4.1 version for now.
TAJO-1: RCFileWrapper always reads whole columns regardless of the target schema (jihoonson via hyunsik)
TAJO-6: Rename tajo.engine.function.builtin.NewSumInt to SumInt (rsumbaly)
TAJO-2: remove all @author tags and update license header (hyunsik)
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/incubator-tajo into NEW_OPTIMIZER3

Conflicts:
	LICENSE.txt
	NOTICE.txt
	tajo-core/tajo-core-backend/src/main/java/tajo/engine/json/FromTableDeserializer.java
	tajo-core/tajo-core-backend/src/main/java/tajo/engine/planner/JoinType.java
	tajo-core/tajo-core-backend/src/main/java/tajo/engine/planner/logical/LogicalNode.java
	tajo-core/tajo-core-storage/src/test/java/tajo/storage/TestStorages.java