Warn/Skip system folder saves

[bucanero]

Apollo should skip/ignore/warn users trying to manage:

BAEXEC-SYSTEM
BIEXEC-SYSTEM
BEEXEC-SYSTEM
BCEXEC-SYSTEM
BAEXEC-DVDPLAYER
BIEXEC-DVDPLAYER
BEEXEC-DVDPLAYER
BCEXEC-DVDPLAYER

these folders have KELF linked to the memcard ID, so they won't work on any other memcard.