Changed the Cheat Search tab to disable the scan buttons while there is
not a game running and enable when it starts. Also added double-click to
create code to the result list.
ISOProperties loads codes using ActionReplay::LoadCodes which actually applies
the codes to the global state. If a game is running then that games receives
all the codes (and ACTIVE status) from the second game being shown in
ISOProperties which is not desirable.
