Add /api/v1/notifications/clear, non-existing link cards for statuses will

now return empty hash instead of throwing a 404 error. When following,
merge into timeline will filter statuses

app/lib/feed_manager.rb

@@ -43,6 +43,7 @@ class FeedManager
     timeline_key = key(:home, into_account.id)
 
     from_account.statuses.limit(MAX_ITEMS).each do |status|
+      next if filter?(:home, status, into_account)
       redis.zadd(timeline_key, status.id, status.id)
     end