GSSAPI s4u2proxy with client keytab initiation and Heimdal KDC

[Greg Hudson]

If you are in a position to conveniently test it, the following patch
should fix FAST TGS against Windows 2008 or Heimdal KDCs (or pre-1.7 MIT
KDCs), without having to disable FAST TGS client support:


https://github.com/greghudson/krb5/commit/414743b7c3f6580ee97299429d7a2514522826ff

Christopher, thanks for reporting this problem back in March, and
apologies that I didn't figure it out back then.