This commit replaces the timestamp based state system with a new
one that has update channels directly to the connected nodes. It
will send an update to all listening clients via the polling
mechanism.
It introduces a new package notifier, which has a concurrency safe
manager for all our channels to the connected nodes.
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
Juan Font
Kristoffer Dalby