include only source and build from our Makefile.
Don't scan for libpopt if we're using our own; this makes
autoconf confused.

Add comments.
Show listening port number in startup log message.

Add comment.

Include more details in --version output: say whether symlinks and
hardlinks are supported.
When hardlink support is missing, explain whether the problem is on
the client or server.
When a bad option is encountered, don't just print it to stderr but
send it to the rsync log mechanism.  (However, server errors currently
seem to get lost in transit because of bugs in logging.)

Automatically build included libpopt if there is none on the system,
or if --with-included-popt is specified.
Add --enable-debug.

Automatically build included libpopt if there is none on the system.

Better error message in the case of eof on read_timeout.

from getopt

about 2.4.6.

than just an RERR code.