Add better logic in bp_is_user_spammer().

Mirror these changes to bp_is_user_deleted() as well.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@6989 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Change logic of bp_stop_live_spammer().

Instead of using wp_die(), reauthorize the user by redirecting the logged-in
spammer to wp-login.php with the 'reauth' parameter.

bp_live_spammer_login_error() adds an error message for the logged-in
spammer on the wp-login.php page.

Fixes #4814.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@6990 cdf35c40-ae34-48e0-9cc9-0c9da1808c22