Patch to handle ACL differences

[Andrew Gideon]

A while ago (2.6.2), I built and posted a patch which caused rsync to "do
the right thing" where --link-dest was being used and where files had been
changed only in their ACLs.  I've recreated this for 2.6.8 (there were
some small differences).

I've tested this using --link-dest copying from Linux-Linux and
Linux-Solaris.  I plan to test Solaris-Solaris too, of course.  

But all the testing I'm doing is for my particular situation: using
--link-dest.  The point is to create backup snapshots using --link-dest
which properly preserve/backup ACL changes.

What else - besides --link-dest use - should I do to test this patch
before I post it?

The main change is in unchanged_attrs(), where this now can detect ACL
changes.

Thanks...

	Andrew