TAJO-44: Adopt AMRMClient to RMContainerAllocator, RMCommunicator. (hyunsik)
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/incubator-tajo into TAJO-44_R

Conflicts:
	tajo-core/tajo-core-backend/src/main/java/tajo/master/QueryMaster.java
	tajo-core/tajo-core-backend/src/main/java/tajo/master/rm/RMContainerAllocator.java