from the waitpid() call.

- Tweaked a couple variable names.
- Changed the #ifdefs to not define any hard-link functions
  when hard-linking is disabled.

32 bits by default, by removing the basename pointer, and by making the
mode value a unsigned short.

  were moved out of file_struct into an optional member-var setup.
- Renamed and reorganized the FLAG_* defines.
- Use NDX_DONE instead of a literal -1 when sending/checking the
  end-of-phase index value.

is used by both the sender and the receiver.

- Improved a comment.

- Improved the SIZEOF_INT64 checking code in write_longint().

- Added explicit char-casting to new long-int code.

  be needed, but it at least works right now).
- Improved the transmission of 32-bit negative numbers on systems
  where the 32-bit type is larger than 32 bits.
- Changed the sending of 64-bit numbers for protocol 30:  we send
  them in MSB-first order with the number of bytes used in the
  transmission encoded into the earliest bits.  This lets us save
  transmitted bytes for both small and large numbers.  The new
  method sends from 3 to 9 bytes, the old sent either 4 or 12.

- Tweaked a variable name in delete_item().

other side.