Add pps option to the refclock directive to force chronyd to treat any
refclock as a PPS refclock. This is intended for refclocks that may
provide time off by a whole number of seconds due to missing or wrong
TAI/GPS->UTC conversion.
Split RCL_AddPulse() in order to provide a new function for refclock
drivers which can make PPS samples without having raw system time, e.g.
from PHC timestamps.
The maxlockage option specifies in number of pulses how old can be
samples from the refclock specified by the lock option to be paired with
the pulses. Increasing this value is useful when the samples are
produced at a lower rate than the pulses.
Replace struct timeval with struct timespec as the main data type for
timestamps. This will allow the NTP code to work with timestamps in
nanosecond resolution.
The minsamples and maxsamples directives now set the default value,
which can be overriden for individual sources in the server/peer/pool
and refclock directives.
