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>
This is a massive commit that restructures the code into modules:
db/
All functions related to modifying the Database
types/
All type definitions and methods that can be exclusivly used on
these types without dependencies
policy/
All Policy related code, now without dependencies on the Database.
policy/matcher/
Dedicated code to match machines in a list of FilterRules
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>