Also, remove all traces of these interfaces from user manual (README
file) and man page (docs/dosbox.1).
MCI (Media Control Interface) was a primary Windows interface. Code
comments and documentation claimed, that it's only for "NT, 2000, XP"
but the code was enabled for Windows 2000 or later (version > 4.0).
DX (Digital audio eXtraction (?)) could be forced on any Windows with
autodetection working only on Vista and Windows 7 (code was disabled for
Windows 8 or later - probably unintentionally).
DIO used DeviceIoControl interface and Windows-specific ioctl calls.
All 3 interfaces depend on SDL and SDL_cdrom functionality to work.
SDL_cdrom 1.2 implementation uses MCI on Windows to provide the same
functionality.
ddda555854
