2011-10-28 18:46 AEST by Arthur Barrett - on windows it would be more efficient to rewrite the rcs file using a memory 
mapped file, eg: pseudocode

  copyfile("rcs,v",",rcs,v")
  mapfile(",rcs,v");
  memmove(a,b,d);
  closemap()

The code is currently structured to 'read' through each 'node' and 'data' - 
this could still be done, just using memcpy() instead of read().