Fix Tajo pull server aux service name.
TAJO-85: Add an method of create(DataType, byte[]) to DatumFactory. (jihoon)
TAJO-86: Improved error messages in query analyzer. (jinho)
TAJO-70: Refactor GlobalEngine to handle DDL statements. (hyunsik)
TAJO-19: CREATE TABLE without external data should be supported. (jinho)
Merge branch 'master' of https://github.com/apache/incubator-tajo into SQL_IMPROVE

Conflicts:
	tajo-core/tajo-core-backend/src/main/antlr4/org/apache/tajo/engine/parser/SQLLexer.g4
	tajo-core/tajo-core-backend/src/main/antlr4/org/apache/tajo/engine/parser/SQLParser.g4
	tajo-core/tajo-core-backend/src/main/java/org/apache/tajo/engine/parser/CreateTableStmt.java
	tajo-core/tajo-core-backend/src/main/java/org/apache/tajo/engine/parser/QueryAnalyzer.java
	tajo-core/tajo-core-backend/src/main/java/org/apache/tajo/engine/planner/LogicalPlanner.java
	tajo-core/tajo-core-backend/src/main/java/org/apache/tajo/master/GlobalEngine.java