And if we have over 10,000 CGNAT routes, just route the entire
CGNAT range. (for the hello test server)
Fixes#1450
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
And move a couple other types down into leafier packages.
Now cmd/tailscale doesn't bring in netlink, magicsock, wgengine, etc.
Fixes#1181
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>