Incorporate graph merge functionality into SMART JS client

[jmandel]

function addGraphs(){
   //add all graphs in arguments to new rdfquery object
   var rq = SMART.$.rdf();

   $.each(arguments, function(){
       rq.databank = rq.databank.add(this.graph.databank,{namespaces:
this.graph.prefix()});
   });

   return rq;
}