handle empty responses
handle empty responses

git-svn-id: 96ec19519756d6256e3201f6113dd23bfeddceae@116 f6d6ccb1-4906-4145-b9cb-3503ec0a5639

geopython/pycsw,bukun/pycsw,rouault/pycsw,mwengren/pycsw,mwengren/pycsw,kalxas/pycsw,tomkralidis/pycsw,ocefpaf/pycsw,PublicaMundi/pycsw,kalxas/pycsw,kevinpdavies/pycsw,benhowell/pycsw,ocefpaf/pycsw,kalxas/pycsw,ingenieroariel/pycsw,bukun/pycsw,ingenieroariel/pycsw,tomkralidis/pycsw,PublicaMundi/pycsw,benhowell/pycsw,kevinpdavies/pycsw,ricardogsilva/pycsw,rouault/pycsw,geopython/pycsw,ckan-fcd/pycsw-fcd,ckan-fcd/pycsw-fcd,ricardogsilva/pycsw,ricardogsilva/pycsw,bukun/pycsw,geopython/pycsw,tomkralidis/pycsw