Added. Explanation for the failed logins and link to documentation

git-svn-id: https://plugins.svn.wordpress.org/sucuri-scanner/trunk@951168 b8457f37-d9ea-0310-8a92-e5e31aec5664
Added. Direct link to edit failed login notifications

git-svn-id: https://plugins.svn.wordpress.org/sucuri-scanner/trunk@951172 b8457f37-d9ea-0310-8a92-e5e31aec5664