Rdiff-backup

Now if rdiff-backup isn't running as root, it doesn't try to change file ownership.

Fixed an error report.

Stopped flushing an open pipe to fix a race condition on IRIX.

rdiff-backup can now operate in a bandwidth efficient manner (a la rsync) using a pipe setup with, for instance, ssh.

I was too hasty with the last bug fix and didn't deal with all filenames properly.
Maybe this one will work.

Bug fix: Filenames that may contain spaces, backslashes, and other special characters are quoted now and should be handled correctly.

Large portion (majority?) of rdiff-backup was rewritten for v0.1.
New version highlights:

* No new features!
* No speed improvements!
It may even be slower...
* No bug fixes!
(ok maybe a few)

However, the new version is much cleaner and better documented.
This version should have fewer bugs, and it should be easier to fix any future bugs.