Relationship dates in profile metadata

Capture relationship dates as a date range within metaItem with about="relationship_dates"

metaItem[@about="relationship_dates"][metaDescribes/@predicate=("isoStart","isoEnd")]

Spouses metadata including relationship dates


      <metaItem about="spouses">
        <metaItem about="spouse"><metaDescribes predicate="gender">f</metaDescribes><metaItem about="name">
 <metaDescribes predicate="type">personal</metaDescribes>
 <metaDescribes predicate="mainName">Braithwaite</metaDescribes>
 <metaDescribes predicate="foreNames">Patricia Mary</metaDescribes>
 <metaItem about="alternative_name">
   <metaDescribes predicate="alt_type">variant</metaDescribes>
   <metaDescribes predicate="foreNames">Pat</metaDescribes>
 </metaItem>
 <metaItem about="alternative_name">
   <metaDescribes predicate="alt_type">alias</metaDescribes>
   <metaDescribes predicate="mainName">Gaskell</metaDescribes>
 </metaItem></metaItem><metaItem about="birth">
 <metaDescribes predicate="date">1929</metaDescribes></metaItem><metaItem about="relationship_dates">
 <metaDescribes predicate="isoStart">1948-08-19</metaDescribes>
 <metaDescribes predicate="isoEnd">1952</metaDescribes></metaItem><metaDescribes predicate="liaison">marriage</metaDescribes><metaDescribes predicate="type">standard</metaDescribes><metaDescribes predicate="spouseID">100008</metaDescribes>
        </metaItem>
        <metaItem about="spouse"><metaDescribes predicate="gender">f</metaDescribes><metaItem about="name">
 <metaDescribes predicate="type">personal</metaDescribes>
 <metaDescribes predicate="mainName">Richardson</metaDescribes>
 <metaDescribes predicate="foreNames">Elizabeth Jill</metaDescribes>
 <metaItem about="alternative_name">
   <metaDescribes predicate="alt_type">variant</metaDescribes>
   <metaDescribes predicate="foreNames">Jill</metaDescribes>
 </metaItem></metaItem><metaItem about="dates">
 <metaDescribes predicate="isoStart">1933</metaDescribes>
 <metaDescribes predicate="isoEnd">2006</metaDescribes></metaItem><metaItem about="relationship_dates">
 <metaDescribes predicate="isoStart">1952-11-01</metaDescribes></metaItem><metaDescribes predicate="liaison">not marriage</metaDescribes><metaDescribes predicate="type">alternate</metaDescribes><metaDescribes predicate="spouseID">100009</metaDescribes>
        </metaItem>
      </metaItem>