Added note about installation with existing WSGI applications
Added note about installation with existing WSGI applications

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