Issue #120: Refactored SimpleJobFactory and WorkflowEngine.
Issue #120: Remved SimpleJobFactory.
Merge branch 'master' into simple-job-factory

Conflicts:
	integration_test/cws/core/scheduler/DAGDynamicSchedulerStorageAwareTest.java
	integration_test/cws/core/scheduler/DAGDynamicSchedulerTest.java
	integration_test/cws/core/scheduler/EnsembleDynamicSchedulerTest.java
	src/cws/core/WorkflowEngine.java
	test/cws/core/scheduler/DAGDynamicSchedulerUnitTest.java