Client should validate the incoming host value

Convert host:port and URLs passed to client.New() into the proper
values, and return an error if the value is invalid.  Change CLI
to return an error if -master is invalid.  Remove Client.rawRequest
which was not in use, and fix the involved tests. Add NewOrDie

Preserves the behavior of the client to not auth when a non-https
URL is passed (although in the future this should be corrected).

cmd/apiserver/apiserver.go

@@ -92,7 +92,10 @@ func main() {
 		Port:   *minionPort,
 	}
 
-	client := client.New("http://"+net.JoinHostPort(*address, strconv.Itoa(int(*port))), nil)
+	client, err := client.New(net.JoinHostPort(*address, strconv.Itoa(int(*port))), nil)
+	if err != nil {
+		glog.Fatalf("Invalid server address: %v", err)
+	}
 
 	m := master.New(&master.Config{
 		Client:             client,