This pretty large change does the following:
- moves nix from bootstrap.hswaw.net to nix/
- changes clustercfg to use cfssl and moves it to cluster/clustercfg
- changes clustercfg to source information about target location of
certs from nix
- changes clustercfg to push nix config
- changes tls certs to have more than one CA
- recalculates all TLS certs
(it keeps the old serviceaccoutns key, otherwise we end up with
invalid serviceaccounts - the cert doesn't match, but who cares,
it's not used anyway)
This is so that Calico starts with the proper subnet. Feeding it just an
IP from the node status will mean it parses it as /32 and uses IPIP
tunnels for all connectivity.