Change default minsamples to 6 and polltarget to 8. This should improve
stability with extremely small jitters (e.g. HW timestamping) and not
decrease time accuracy at minimum polling interval too much.
This is an incompatible change in the output of the tracking command,
which may break some scripts, but it's necessary to avoid confusion with
IPv4 addresses when synchronised to an IPv6 server or reference clock.
Enable the PRV_Name2IPAddress() function with seccomp support and start
the helper process before loading the seccomp filter (but after dropping
root privileges). This will move the getaddrinfo() call outside the
seccomp filter and should make it more reliable as the list of required
system calls won't depend on what glibc NSS modules are used on the
system.
