Automatic merge from submit-queue

Edge-based userspace LB in kube-proxy

@thockin @bowei - if one of you could take a look if that PR doesn't break some basic kube-proxy assumptions. The similar change for winuserproxy should be pretty trivial.

And we should also do that for iptables, but that requires splitting the iptables code to syncProxyRules (which from what I know @thockin already started working on so we should probably wait for it to be done).