This one alone doesn't modify the global dependency map much
(depaware.txt if anything looks slightly worse), but it leave
controlclient as only containing NetworkMap:
bradfitz@tsdev:~/src/tailscale.com/ipn$ grep -F "controlclient." *.go
backend.go: NetMap *controlclient.NetworkMap // new netmap received
fake_test.go: b.notify(Notify{NetMap: &controlclient.NetworkMap{}})
fake_test.go: b.notify(Notify{NetMap: &controlclient.NetworkMap{}})
handle.go: netmapCache *controlclient.NetworkMap
handle.go:func (h *Handle) NetMap() *controlclient.NetworkMap {
Once that goes into a leaf package, then ipn doesn't depend on
controlclient at all, and then the client gets smaller.
Updates #1278
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>
