Use WP Query instead of a direct db query
only return IDs from query
don't need global $wpdb
exclude manual related posts from related post query
Merge branch 'refs/heads/master' into use-wp-query
remove comment
Merge pull request #3 from humanmade/use-wp-query

Use wp query
Merge branch 'refs/heads/master' into sanitize-ajax
Merge branch 'sanitize-ajax' of github.com:mattheu/HM-Related-Posts into sanitize-ajax
Pass array to add_query_arg