Fix for issues for:
https://jira.intersect.org.au/browse/HCSVLAB-917?focusedCommentId=68748&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-68748

Fix multiple documents parsing issues
Fix freely added extra attributes not in rdf issue
Fix extra speaker attributes not in rdf issue
Fix multiple speakers parsing issues