[krbdev.mit.edu #2545] AFS string_to_key broken for passwords > 8 chars

[Sam Hartman via RT]

One work around might be to convince the Heimdal KDC to send the
appropriate etype_info2 s2kparams to indicate that the AFS3 salt
should be used.  If your KDC does this, our code should do the right
thing.