added settings
added settings

fixes #182

dshanske/wordpress-semantic-linkbacks,pfefferle/wordpress-semantic-linkbacks,pfefferle/wordpress-semantic-linkbacks,dshanske/wordpress-semantic-linkbacks,pfefferle/wordpress-semantic-linkbacks,pfefferle/wordpress-semantic-linkbacks,dshanske/wordpress-semantic-linkbacks,dshanske/wordpress-semantic-linkbacks