2.46 (07 Apr 2001):
  Removed system variables for file/load/print/exec types.
2.47 (07 Apr 2001):
  Fix for ioctl on unopened files.
2.48 (16 May 2001):
  Fix from Daniel Ellis to leave streams open if they error.
2.49 (08 Aug 2001):
  Added FSControl FileSwitchInfo.
2.49 (retagged) (10 Aug 2001):
  Fix for minor mistake in FileSwitchInfo SWI.
2.50 (16 Mar 2002):
  Changed name of copy dynamic area.
