Yet another magic symlinks implementation

[Lamont Granquist]

AFS also has an @sys variable which is useful for network filesystem 
mounted binaries and software for multiple architectures through a single 
globally unique path:

http://www.openafs.org/pages/doc/AdminReference/auarf234.htm#HDRSYS

And I'd vote with Oliver on preferring variant symlinks for flexibility:

On Mon, 6 Nov 2006, Oliver Fromme wrote:
> I'm afraid that I don't like NetBSD's "magic symlinks" very
> much.  It's less flexible than variant symlinks because it
> only supports a fixed set of variables.  As far as I can
> tell, it does not solve any of the tasks described above.
>
> Therefore I would really like to see your port of DragonFly
> BSD's variant symlinks comitted to FreeBSD.  Of course, it
> could be a compile-time option in case there are people who
> don't want the code in their kernel at all.  But you have
> to set a sysctl anyway to enable it globally (it's disabled
> by default on DragonFly).