I could not find a lot of precedence for this, because most time
daemons do not actually look at the value of olddelta. Account for
olddelta getting stuck at 1ms, and for a NULL value of delta being
treated as an error condition.

Due to some circular dependencies on Solaris, this needs to be defined
as a macro. We should just remove SA_LEN usage here next.

If sa_family is not set, sa_len should be zero.

I removed all of the code in fake-sensors, I don't think Henning wants
all the credit for an empty file.

TODO: convert u_int_* types to uint_*