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>
