Defines starting with `d' in src/od-win32

• DBG_KEYBD src/od-win32/keyboard.c:34
• diff src/od-win32/posixemu.c:41
• DIRECT_SOUND_ENABLED src/od-win32/win32gui.h:32
• DISK_FORMAT_STRING src/od-win32/win32gui.c:54
• DRIVE_WIDTH src/od-win32/win32.h:80