new feature: added field to add class to widget container as well.

git-svn-id: https://plugins.svn.wordpress.org/text-widget-with-class/trunk@973562 b8457f37-d9ea-0310-8a92-e5e31aec5664
updated minor text

git-svn-id: https://plugins.svn.wordpress.org/text-widget-with-class/trunk@973564 b8457f37-d9ea-0310-8a92-e5e31aec5664