Implementation of XLIFF 2.1 - ITS module

<source>
               <itsAnn xmlns=""/>
               <sm id="sm1"
                   type="itsm:generic"
                   itsm:taClassRef="http://nerd.eurecom.fr/ontology#Place"
                   itsm:taIdentRef="http://dbpedia.org/resource/Arizona">
                  <itsAnn xmlns="">
                     <elem>
                        <taClassRefPointer xmlns:xlf2="urn:oasis:names:tc:xliff:document:2.0"
                                           xmlns:its="http://www.w3.org/2005/11/its"
                                           xmlns:datc="http://example.com/datacats"
                                           itsm:taClassRef="http://nerd.eurecom.fr/ontology#Place"/>
                        <taIdentRefPointer xmlns:xlf2="urn:oasis:names:tc:xliff:document:2.0"
                                           xmlns:its="http://www.w3.org/2005/11/its"
                                           xmlns:datc="http://example.com/datacats"
                                           itsm:taIdentRef="http://dbpedia.org/resource/Arizona"/>
                     </elem>
                  </itsAnn>
               </sm>Arizona<em startRef="sm1">
                  <itsAnn xmlns=""/>
               </em>
            </source>