TAJO-1101: Broadcast join with a zero-length file table returns wrong result data.

Closes #184
TAJO-1103: Insert clause of partitioned table loses some FetchImpls. (jinho)

Closes #186
TAJO-1010: Improve multiple DISTINCT aggregation. (Hyoungjun Kim and jaehwa)

Closes #136
TAJO-1097: IllegalArgumentException: RawFileScanner. (Mai Hai Thanh via jinho)

Closes #183
Merge branch 'master' of http://git-wip-us.apache.org/repos/asf/tajo into TAJO-838

Conflicts:
	tajo-core/src/main/java/org/apache/tajo/engine/planner/PhysicalPlannerImpl.java
TAJO-838