Release 1.7.4

Version 1.7.4

• As fork and wait do not exist on Windows writing compressed files
  through pipe/fork/exec/wait has to be disabled for Windows cross
  compilation to go through. Alternatively one could go back to popen
  for writing compressed files on Windows which however is not safe and
  therefore we simply decided to disable that feature for windows.
  Compressed file reading still (and as far we are aware safely) uses
  popen and thus also compiles for Windows.