Allow multiple NTP servers, also with runtime configurable list
Add validation of received NTP packets
NTPv4 support with 'Kiss o' Death' message handling
IPv6 support
Collect multiple NTP samples and filter outsiders
Check if system clock has been altered during NTP (if CONFIG_CLOCK_MONOTONIC)
Signed-off-by: Juha Niskanen <juha.niskanen@haltian.com>