rename grid to network (for consistency) and activity to stream (as seen in osada) because it makes much more sense.

(cherry picked from commit 96277372d5)

Zotlabs/Module/Network.php

@@ -164,7 +164,7 @@ class Network extends \Zotlabs\Web\Controller {
 				));
 			}
 	
-			nav_set_selected('Grid');
+			nav_set_selected('Network');
 
 			$channel_acl = array(
 				'allow_cid' => $channel['channel_allow_cid'],