permanent fix for Undefined Index issue; plugin now checks and displays form in local language (use WPLANG in wp-config.php to define your language); admin CSS and page updates; improved onblur and onfocus events for textboxes

git-svn-id: https://plugins.svn.wordpress.org/feedburner-optin-form/trunk@938117 b8457f37-d9ea-0310-8a92-e5e31aec5664