Fix gaps issues

* In layout command, arrange parent of parent - not sure why this is
needed but it is
* Remove gap adjustment when rendering
* Workspace should use outer gaps, not inner
* Add exceptions for tabbed and stacked containers
* Don't mess with gap state when splitting a container

sway/commands/layout.c

@@ -103,7 +103,7 @@ struct cmd_results *cmd_layout(int argc, char **argv) {
 			parent->prev_split_layout = prev;
 		}
 		container_notify_subtree_changed(parent);
-		arrange_windows(parent);
+		arrange_windows(parent->parent);
 	}
 
 	return cmd_results_new(CMD_SUCCESS, NULL, NULL);