epic epoch work

Made epoch_year a static member with accessor/mutator so that different
epochs can be selected at run time.  This will allow NTP to do its
calculations WRT the NTP epoch, while the rest of the system runs on a
more-efficient epoch.
Added parse method to match operator <<.
Added use_fastest_epoch method to configure time_t to run as quickly as
possible.
Removed timing and old code comments.
Fixed minor bug at for epoch years that don't end in 00.
CosaTime now has numerous tests for clock_t conversions and performance
measurements (log file added).