Jean-Claude BAU authored Oct 10, 2018 and Adam Wujek committed Nov 21, 2018

In the ptp servo the adjustment of the time was too slow. When the
difference of the time with the master was less than 1 second, the
adjustment was done only with the frequency. In case if the difference
is 0.999s, it can take a very long time to adjust the time.
Changes made :
- Adjust with frequency only when time difference is below 20ms
- Check the timestamp validity before each calculation
- Create a new function to check the timestamps and use it on all
servos. This improve significantly the size of the code.
- Add verification in order not to set an invalid UNIX time