Windows: how to get high resolution time in PRNG

[Greg Hudson]

On Tue, 2011-08-09 at 16:09 -0400, Sam Hartman wrote:
> How do we want to fix this? 

My preferred design would be:

1. Add a gettimeofday() equivalent to libkrb5support, prototyped in
k5-platform.h.  Best if the API looks like gettimeofday() to callers
(#defined to k5_gettimeofday on platforms which don't have native
gettimeofday) but if that causes problems it's not a hard requirement.

2. Use that function in prng_fortuna.c and c_ustime.c.

The mutex and massaging code in c_ustime.c can stay where they are.