toLibxmlNode(XMLnode) -- convert a hashtable of type XMLnode to an object of type LibxmlNode

i1 : new XMLnode from {
          tag => "foo",
          children => {
               new XMLnode from {
                    tag => "bar",
                    children => { " chicken coop " } },
               " hi there ",
               new XMLnode from { tag => "bar" } } }

o1 = <foo
       <bar " chicken coop "
       " hi there "
       <bar

o1 : XMLnode

i2 : toLibxmlNode oo

o2 = <foo><bar> chicken coop </bar> hi there <bar/></foo>

o2 : LibxmlNode (xmlTypeDescription)