Before this commit the 'Timestamp' line was always printed
for all versions of GUID, even for non-time-based ones.
Plus, only the time_low field was used, and it was used as if
it contained seconds since UNIX Epoch, which it didn't. In fact
this field along with other time_* fields constitute a single
60-bit value representing the count of 100ns intervals since
adoption of Gregorial calendar (00:00:00.00 15 Oct 1582).
For non-time-based versions of GUID, the time_* fields do
not represent any time at all.
So, after this commit, the timestamp will be properly decoded
for time-based GUID version 1 only. For other versions the
'Timestamp' line will not be displayed. A line showing the
GUID version will be added to the output.
Partially resolvesipmitool/ipmitool#25
Signed-off-by: Alexander Amelkin <alexander@amelkin.msk.ru>