Dragon's Lair Enhancement support

[icculus]

So there's a patched ROM for the arcade cabinet called Dragon's Lair Enhancement ("dle"), that fixes some bugs in the original ROM, adds in some scenes, and changes game flow. It might be neat if there were a setting to make lair function in the same way.

The general idea:

http://dragons-lair-project.com/tech/enhancements/dle21.asp

The scene manager changes:

http://dragons-lair-project.com/tech/enhancements/dle2xsequence.asp

I probably wouldn't mess with prototype mode, since it needs footage from the 2002 Special Edition disc, which I can't guarantee is available, and other things are unique to the arcade cabinet (bug fixes, pay-as-you-go details, etc).

This would just be a cvar to enable a different scene manager, etc, in the existing lair Lua code, so you'd run it like

./dirksimple lair --set dle true

(or switch the setting on in the libretro UI.)