[krbdev.mit.edu #6008] use of incorrect or unknown principal types

[Ken Raeburn via RT]

I tweaked the KDC logging to record the principal name types used in AS and TGS requests, 
and ran the main dejagnu tests.  Mostly things look okay, except:

krbtgt/KRBTEST.COM at KRBTEST.COM always has type NT-UNKNOWN (0).  We construct these 
specially in the client code; we should always be able to specify NT-SRV-INST (2).

The kadmin/admin and kadmin/changepw principals always use NT-PRINCIPAL, but I think 
probably they should be NT-SRV-INST too.

The kadmin/fqdn principal always has type NT-PRINCIPAL (1); it should probably be NT-
SRV-HST (3).

The other service principal types (host, ftp, gssservice, and sample host-based services) all 
were correctly specified as NT-SRV-HST.

There were some cases where the client principal name type didn't get logged, but in those 
where it did, it appears to be correct.