improved unit test for DefaultTemplateFilesResolver

Change-Id: Iaf7b21ff4db7b9eeca74c54c3786423bc8c30857
introduced some unit tests, more to follow

Change-Id: I82b9e44b0495062b61f36fad8f4bbc77355f597e
cosmetic updates

Change-Id: I539faf461ae1baa8479e8e4af670c58d4c4540f5