Removed menu option for making a datfile with both arcade games and Megadrive games, the two would conflict, and arcade and Megadrive dats need to be handled seperately.Added better SRAM support and support for custom mappers as per MESS
Increased the maximum number for sek handlers to 10.Made the short name in the game selection dialog slightly longer to accomodate the Megadrive short names.Made the seventh rom path special like the eighth one so that Megadrive roms can be stored in one of the last two paths and still allow supplementary FB Alpha roms to be in a seperate path.Updated Megadrive driver based on MESS 0.143u7 software list.
