deleting old files

git-svn-id: https://plugins.svn.wordpress.org/article-difficulty-level/trunk@809633 b8457f37-d9ea-0310-8a92-e5e31aec5664
new readme updated 2.0

git-svn-id: https://plugins.svn.wordpress.org/article-difficulty-level/trunk@809634 b8457f37-d9ea-0310-8a92-e5e31aec5664