Add native postgis spatial queries support (#124)
Add native postgis spatial queries support (#124)

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