various enhancements focused on easier configuration of listings and their results. Upgrading plugin version

git-svn-id: https://plugins.svn.wordpress.org/bepro-listings/trunk@871893 b8457f37-d9ea-0310-8a92-e5e31aec5664
tweak documentation

git-svn-id: https://plugins.svn.wordpress.org/bepro-listings/trunk@871895 b8457f37-d9ea-0310-8a92-e5e31aec5664