delete all files feature is more powerful

git-svn-id: https://plugins.svn.wordpress.org/wp-fastest-cache/trunk@809259 b8457f37-d9ea-0310-8a92-e5e31aec5664
delete all files feature is more powerful

git-svn-id: https://plugins.svn.wordpress.org/wp-fastest-cache/trunk@809260 b8457f37-d9ea-0310-8a92-e5e31aec5664