deprecating kerbsrc.zip

[Benjamin Kaduk]

On Wed, 19 Sep 2012, Chris Hecker wrote:

>
> I don't use the kerbsrc.zip path, but I do build the main tree on
> windows, which uses some targets that might overlap with kerbsrc.zip, so
> please don't remove prep-windows et al.

prep-windows will definitely stay around, as it remains part of the 
(non-kerbsrc.zip) build procedure.  The plan is to keep master buildable 
on windows so that future KfW releases will require less effort to 
produce, and they can be produced more frequently.

-Ben