#403 disabled dtd download by default
#403 SystemEnvironemnt is now passed to XmlArtifactImporter, using inavlid domain for non existant dtd for test
Merge pull request #405 from pshivana/issue_403

#403 disabled dtd download by default
#403 injecting SystemEnvironment to StageResourceImporter constructor used by tests
Merge pull request #407 from pshivana/master

#403 injecting SystemEnvironment to StageResourceImporter all constructors