Use Gtk.Menu.detach() correctly

Use Gtk.Menu.detach() only if menu is attached to a widget.

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Don't try to load web apps from an empty directory

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Don't log generated desktop file

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Wait for web worker IPC server

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>