corrected some spelling mistakes


git-svn-id: https://plugins.svn.wordpress.org/brutal-cache/trunk@786073 b8457f37-d9ea-0310-8a92-e5e31aec5664
corrected some spelling in readme


git-svn-id: https://plugins.svn.wordpress.org/brutal-cache/trunk@786078 b8457f37-d9ea-0310-8a92-e5e31aec5664