r9084: 'resign' the sample PAC for the validation of the signature algorithms.

r9084: 'resign' the sample PAC for the validation of the signature algorithms.

If we ever get problems with the kerberos code, it should show up as a
different signature in this PAC.

This involved returning more data from the pac functions, so changed
some callers and split up some functions.

Andrew Bartlett
(This used to be commit d514a7491208afa0533bf9e99601147eb69e08c9)