Fixup axis order, and srs in wfs client mode.

For WFS client: fixup axis order, always include SRSNAME and, in case of WFS 1.1, add SRS in BBOX parameter. Based on patch http://trac.osgeo.org/mapserver/attachment/ticket/4228/ms_wfs-1.1.0-v02.patch from mapserver/mapserver#4228