DPADD does not do anything

[Eirik Nygaard]

I have been updating kerberos5 to heimdal 0.6.3 based on the patches by Richard
Nyberg and ended up with a problem related to the DPADD variable. As of now it
does not do anything, which I found misleading. I ended up adding support for it
to bsd.prog.mk, it should probably be added to bsd.lib.mk as well, perhaps other
places as well.

If noone have objections on the patch I will commit it in a day or two, and it
will be followed by the kerberos update.

http://leaf.dragonflybsd.org/~eirikn/DPADD.patch

-- 
Eirik Nygaard