Minor bugfixes and improvements

git-svn-id: https://plugins.svn.wordpress.org/advanced-custom-fields-sites-field/trunk@1012642 b8457f37-d9ea-0310-8a92-e5e31aec5664
Minor fixes

git-svn-id: https://plugins.svn.wordpress.org/advanced-custom-fields-sites-field/trunk@1012647 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fixed subversion stuff

git-svn-id: https://plugins.svn.wordpress.org/advanced-custom-fields-sites-field/trunk@1012648 b8457f37-d9ea-0310-8a92-e5e31aec5664
tweaked readme description

git-svn-id: https://plugins.svn.wordpress.org/advanced-custom-fields-sites-field/trunk@1012652 b8457f37-d9ea-0310-8a92-e5e31aec5664