fix xpath handling and set ElementSetName if canned XML request
fix xpath handling and set ElementSetName if canned XML request

bird-house/OWSLib,menegon/OWSLib,datagovuk/OWSLib,jaygoldfinch/OWSLib,tomkralidis/OWSLib,QuLogic/OWSLib,mbertrand/OWSLib,gfusca/OWSLib,geographika/OWSLib,dblodgett-usgs/OWSLib,datagovuk/OWSLib,KeyproOy/OWSLib,b-cube/OWSLib,daf/OWSLib,geopython/OWSLib,kalxas/OWSLib,JuergenWeichand/OWSLib,jachym/OWSLib,ocefpaf/OWSLib,Jenselme/OWSLib,jaygoldfinch/OWSLib,daf/OWSLib,robmcmullen/OWSLib,kwilcox/OWSLib,datagovuk/OWSLib,daf/OWSLib