awful.layout: re-arrange on hide property change

Signed-off-by: Julien Danjou <julien@danjou.info>

client.c

@@ -1472,6 +1472,7 @@ luaA_client_newindex(lua_State *L)
             client_need_arrange(c);
             c->ishidden = b;
             client_need_arrange(c);
+            hook_property(client, c, "hide");
         }
         break;
       case A_TK_MINIMIZED:

lib/awful/layout/init.lua.in

@@ -101,7 +101,8 @@ hooks.property.register(function (c, prop)
         or prop == "fullscreen"
         or prop == "maximized_horizontal"
         or prop == "maximized_vertical"
-        or prop == "border_width" then
+        or prop == "border_width"
+        or prop == "hide" then
         on_arrange(c.screen)
     end
 end)