Made sure search is case insensitive

git-svn-id: https://plugins.svn.wordpress.org/acf-field-selector-field/trunk@1026633 b8457f37-d9ea-0310-8a92-e5e31aec5664
Updated readme and version number

git-svn-id: https://plugins.svn.wordpress.org/acf-field-selector-field/trunk@1026635 b8457f37-d9ea-0310-8a92-e5e31aec5664