- A few spelling fixes.

the BATCH.sh file.

call (with extra arg).

  server-excluded file.
- If get_tmpname() fails we need to discard the update using
  receive_data().

characters and spaces in args, omit all the source args, omit the
include/exclude args if we can).

user specified a trailing '=VALUE' or put the value in a separate
arg.

write_sbuf(), and write_byte().

- Fixed the sentence describing how to read standard input with
  --read-batch.

symlinks and devices.

functions seemlessly work on fds that aren't for the main socket. This
involved changing some fd-variable names (to make them clearer), adding
io_set_sock_fds(), and making input buffering have a better enabled
flag (via an allocated buffer, just like the output buffering).  I also
got rid of the fd arg to some functions where the fd arg could only
specify the input or output fd for the socket (which we already know).

- Call io_set_sock_fds().

- Set max_map_size based on the current file's block size (so that
  map_ptr() is more efficient with large blocks).

of the unrelated MAX_MAP_SIZE.

- Improved the warning if a batch option gets sent to the server.

without first transferring the batch file.

need the character buffers and so that it properly removes the
hostname from the destination arg.

is now fully set before the generator forks).

calling local_child().