storage/archive/azio.c:
  Build fixes for not having zutil.h
  
  use memset instead of zmemzero.
  
  use 8 as memory usage level (the default, which we were using anyway)
  
  in the .gz header, just say we're UNIX.
  
  use memcpy instead of zmemcpy.
storage/archive/azlib.h:
  don't use zutil.h, it's private to zlib