Add multiple fifo queue.
Merge branch 'taskAlloc' of https://github.com/jinossy/tajo into multiple-fifo-queue

Conflicts:
	tajo-core/src/main/java/org/apache/tajo/scheduler/AbstractScheduler.java
	tajo-core/src/main/java/org/apache/tajo/scheduler/MultiQueueFiFoScheduler.java
	tajo-core/src/main/java/org/apache/tajo/scheduler/Scheduler.java
	tajo-core/src/main/resources/webapps/admin/scheduler.jsp
TAJO-861: tajo-dump script are not executable. (jinho)
TAJO-862: Restore failure of dumped relations. (jihoon)
Merge branch 'taskAlloc' of https://github.com/jinossy/tajo into multiple-fifo-queue
Configuration reloading feature
Disable queue property reloader
removed useless code
Merge branch 'taskAlloc' of https://github.com/jinossy/tajo into taskrunner
TAJO-847: Supporting MariaDB-based Store, which is compatible with MySQL. (Jinhang Choi via jihoon)
implemented task runner events
 TAJO-880: NULL in CASE clause occurs Exception. (Hyoungjun Kim via hyunsik)

 Closes #40
TAJO-848: PreLogicalPlanVerifier::visitInsert need to find smaller expressions than target columns for a partitioned table. (jaehwa)
TAJO-879: Some data is missing in the case of BROADCAST JOIN and multi-column partition. (Hyoungjun Kim via jaehwa)
TAJO-850: OUTER JOIN does not properly handle a NULL. (Hyoungjun Kim via hyunsik)

Closes #22
TAJO-853: Refactoring FilterPushDown for OUTER JOIN. (Hyoungjun Kim via hyunsik)

Closes #28
TAJO-886: Add IRC page to community section in site.

Closes #45
TAJO-882: CLI hangs when a error occurs in the GlobalPlanner. (Hyoungjun Kim via hyunsik)

Closes #42
TAJO-887: Eliminate HiveQL support feature.

Closes #46
TAJO-887: Eliminate HiveQL support feature. (missed elimination of hiveql config).