--master flag is still supported for distros that need it.
But now, --kubeconfig flag can be used instead, or in addition,
to specify the auth info, and/or the location of the master.
A subsequent PR will change salt to generate a kubeconfig,
and to make kube-proxy use it, for salt-based clouds.
It currently is impossible to use two healthz handlers on different
ports in the same process. This removes the global variables in favor
of requiring the consumer to specify all health checks up front.
All the distros that use this have been updated,
or have PRs out to update them, or owners
have been asked to fix RPMs.
Removing this prevents further use of this model.
Remove now dead code: EtcdClientOrDie
Remove now dead pkg/proxy/config/etcd.go.
Remove unused imports.
