Remove global map from healthz

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.

cmd/kube-controller-manager/controller-manager.go

@@ -26,12 +26,17 @@ import (
 	"runtime"
 
 	"github.com/GoogleCloudPlatform/kubernetes/cmd/kube-controller-manager/app"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/healthz"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/version/verflag"
 
 	"github.com/spf13/pflag"
 )
 
+func init() {
+	healthz.DefaultHealthz()
+}
+
 func main() {
 	runtime.GOMAXPROCS(runtime.NumCPU())
 	s := app.NewCMServer()