Implement a ServiceController that watches services and handles keeping

external load balancers up-to-date based on the service's specs, using
the new DeltaFIFO watch queue class. Remove the old registry REST
handler code for creating/updating/deleting load balancers.

Also clean up a bunch of the GCE cloudprovider code related to load balancers.

pkg/cloudprovider/cloud.go

@@ -50,6 +50,8 @@ func GetLoadBalancerName(clusterName, serviceNamespace, serviceName string) stri
 type TCPLoadBalancer interface {
 	// TCPLoadBalancerExists returns whether the specified load balancer exists.
 	// TODO: Break this up into different interfaces (LB, etc) when we have more than one type of service
+	// TODO: This should really return the details of the load balancer so we can
+	// determine if it matches the needs of a service rather than if it exists.
 	TCPLoadBalancerExists(name, region string) (bool, error)
 	// CreateTCPLoadBalancer creates a new tcp load balancer. Returns the IP address or hostname of the balancer
 	CreateTCPLoadBalancer(name, region string, externalIP net.IP, ports []int, hosts []string, affinityType api.AffinityType) (string, error)