Add TestWriter class which is used to test modifications done via. Workflow->process()
Correct Interface implementation for TestWriter.
Add Test for mapping an Item.
Add Global-Mapping functionality.
Fix merge conflict.
Fix typo.
Rename/move TestWriter to ArrayWriter in Writer-Namespace.
Fix typo in documentation and PHPDoc.
Fix PHPDoc.
Fix CS.
Fix CS.
Merge pull request #24 from gries/global_item_mapping

Global item mapping