Yet another magic symlinks implementation

[Andrey V. Elsukov]

>This code really needs some work though.  First of all, macros should 
>never operate on variables not passed in as arguments.  The SUBSTITUTE 
>macro should be a function.  The matching algorithm is not very efficient 
>either.

First of thank to all for the attention and spent time.
I've tried port this feature after Roman ask. And this is mostly a copy
of code from NetBSD. If somebody from commiters want commit this, i can
rewrite code.

-- 
WBR, Andrey V. Elsukov