in --itemized-changes mode.  If the item is not being updated,
  either pass it along to the receiver (if we're the server) or just
  call log_send().
- We reject an attempt to file-update any non-regular file, not just
  dirs.
- Avoid the verbose "log the transfer" output if --log-format was
  specified and log_before_transfer is in effect.
- Call log_send() with its new iflags arg.