- 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.

- The msgtype var should have been an enum.

some systems.

- Some bf(...) tweaks.

on a system with lutimes() anyway).