[CORE] Make avatars be served with the same mechanism as attachments

lib/util/default.php

@@ -147,8 +147,8 @@ $default =
             array('jpegquality' => 85),
         'avatar' =>
             array('server' => null,
-                'dir' => PUBLICDIR . '/avatar/',
-                'path' => $_path . '/avatar/',
+                'dir' => INSTALLDIR . '/file/avatar/',
+                'url_base' => $_path . '/avatar/',
                 'ssl' => null,
                 'maxsize' => 300),
         'foaf' =>

lib/util/router.php

@@ -1040,6 +1040,10 @@ class Router
                             ['nickname' => Nickname::DISPLAY_FMT]);
             }
 
+            $m->connect('avatar/:file',
+                        ['action' => 'avatar'],
+                        ['file' => '.*']);
+
             $m->connect(':nickname/avatar',
                         ['action' => 'avatarbynickname'],
                         ['nickname' => Nickname::DISPLAY_FMT]);