Fixed tests and replaced DummyWorkflow by BaseWorkflow
- fixed some failing unit tests.
- eliminated the DummyWorkflow class by using the BaseWorkflow class directly instead.
- BaseWorkflow: renamed inputs and outputs fields to inputsFiles and outputsFiles (used in GalaxyWorkflow too).
- ConcatenateExample: added OUTPUT_NAME field and used it in ConcatenateExampleTest.
- HistogramExample: added OUTPUT_NAME field and used it in HistogramExampleTest.
- TestGuiceModule, DummyWorkflowEngineFactory and DummyWorkflowEngine: added Javadocs and copyright/license information.