Make the public streams ModeratedNoticeStream (hide sandboxed users etc.)

Which streams should be put under ModeratedNoticeStream is probably open
to debate. But at least the public ones should hide the posts from users
that are sandboxed.

lib/moderatednoticestream.php

@@ -0,0 +1,39 @@
+<?php
+
+if (!defined('GNUSOCIAL')) { exit(1); }
+
+/**
+ * Moderated notice stream, will take into account the scoping of
+ * notices as well as whether the profile is moderated somehow,
+ * such as by sandboxing or silencing.
+ *
+ * Inherits $this->scoped from ScopingNoticeStream as the Profile
+ * this stream is meant for. Can be null in case we're not logged in.
+ *
+ * @category  Stream
+ * @package   GNUsocial
+ * @author    Mikael Nordfeldth <mmn@hethane.se>
+ * @copyright 2016 Free Software Foundation, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
+ * @link      https://gnu.io/social
+ */
+
+class ModeratedNoticeStream extends ScopingNoticeStream
+{
+    protected function filter(Notice $notice)
+    {
+        if (!parent::filter($notice)) {
+            return false;
+        }
+
+        // If the notice author is sandboxed
+        if ($notice->getProfile()->isSandboxed()) {
+            // and we're either not logged in OR we aren't some kind of privileged user that can see spam etc.
+            if (!$this->scoped instanceof Profile || !$this->scoped->hasRight(Right::REVIEWSPAM)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}

lib/networkpublicnoticestream.php

@@ -2,7 +2,7 @@
 
 if (!defined('GNUSOCIAL')) { exit(1); } 
 
-class NetworkPublicNoticeStream extends ScopingNoticeStream
+class NetworkPublicNoticeStream extends ModeratedNoticeStream
 {
     function __construct(Profile $scoped=null)
     {

lib/publicnoticestream.php

@@ -41,7 +41,7 @@ if (!defined('GNUSOCIAL')) { exit(1); }
  * @link      http://status.net/
  */
 
-class PublicNoticeStream extends ScopingNoticeStream
+class PublicNoticeStream extends ModeratedNoticeStream
 {
     function __construct(Profile $scoped=null)
     {