recursion by eliminating the need for a MAXPATHLEN buffer in
send_if_directory().  Also improved a few variable names in
send_file_list().

- Added an error message to wait_process_with_flush() that
  reports the errno we get when waitpid() fails.
- Increased the value of MAXCHILDPROCS.

request info and puts that into the environment as RSYNC_REQUEST.

and used it in the new wait_process_with_flush() function (the old
function's new name).  Made wait_process() public.

preserve the first /./ dir so that we can use its position to
trim the implied directories.

if the option is combined with --ignore-existing.

instead of --existing.

ten instead of binary K/M/G powers, and so that it can be told to
add or subtract one from the result.  We also make sure to pass
the arg to --max-size in a compatible manner with older versions.