ResourceLoader overzealously validates XML documents such that it will attempt but fail to validate documents not possessed of a document type. ResourceLoader's special handling for PersonDirs.xml is not threadsafe -- it changes the validation flag on the core document builder factory shared by other threads of execution.

This change introduces a try-catch approach to trying to validate but falling back to not validating where validation fails, and uses two dedicated document builder factories, one validating and one not, to restore threadsafety.

See UP-1197