[krbdev.mit.edu #7532] still not ready for kvnos over 255

[Benjamin Kaduk via RT]

kadmin's ktadd, klist -k, and ktutil wrap the displayed kvno at 8 bits.  kadmin's getprinc shows 
the correct value.

For extra fun, kadmin ktremove old picks the wrong entry of the "current kvno" to remove, at 
least sometimes.