Various changes to DC GD-Rom device, improved status register, moved ATAPI commands behind a timer

git-svn-id: svn://dspnet.fr/mame/trunk@24932 749742ba-7341-0410-aadc-df50b521781e
HISCORE DIFF's for all MAME versions without hiscore support

The diff performs the following:
1) Adds hiscore support back into MAME
2) Removes all nag screens
3) Removes loading messages (decoding/decrypting/Updating Artwork, etc.) and the 'white box' when loading.

 Add the following to the mame.ini file to disable the appropiate patch section:

disable_hiscore_patch   1   <- To disable highscore support. Set to 0 or omit it entirely from ini file to enable.
disable_nagscreen_patch   1  <- To disable removal of nagscreens /white box. Set to 0 or omit it entirely from ini file to enable.
disable_loading_patch   1      <- To disable suppresssion of loading/decypting/etc messages. Set to 0 or omit it entirely from ini file to enable.
Adding the GroovyMame's patch