C: work around bug in 'file' command by removing it.

Bug in File 5.19 reported to the 'file' bug tracker:

http://bugs.gw.com/view.php?id=372
C: fix crash on Win32 systems, introduced by f9871240

fflush() does not work on WIN32 handles.
C: add check for command line overflow
C: Add support for MTP-2 Nx64 channels