bluetooth: Make insensitive when locked

Most system menu entries are disabled on the lock/login screen;
there is no good reason why users should be allowed to turn bluetooth
on/off (but not e.g. Wifi), so disable the entry as well.

https://bugzilla.gnome.org/show_bug.cgi?id=726319
location: Make insensitive when locked

Most system menu entries are disabled on the lock/login screen,
there is no good reason for the location entry to be an exception.

https://bugzilla.gnome.org/show_bug.cgi?id=726319