Change from getopt to popt.

Change from getopt to popt.
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.)