TAJO-1125: Separate logical plan and optimizer into a maven module.

Closes #210
TAJO-1125: Separate logical plan and optimizer into a maven module. (missed jar copy)
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/tajo into index_support

Conflicts:
	tajo-plan/src/main/java/org/apache/tajo/plan/visitor/BasicLogicalPlanVisitor.java
	tajo-plan/src/main/java/org/apache/tajo/plan/visitor/LogicalPlanVisitor.java