make HTTP Update Server more secure (#2104)

* make HTTP Update Server more secure

* added option for authentication
* added option to change the url for upload

* move to overloaded setup

* remove delay in both examples

* Get better result responses

* fix strings

interesting, the meta did not refresh if the successResponse is put in
"R"

libraries/ESP8266HTTPUpdateServer/examples/SecureWebUpdater/SecureWebUpdater.ino

@@ -0,0 +1,45 @@
+/*
+  To upload through terminal you can use: curl -F "image=@firmware.bin" esp8266-webupdate.local/update
+*/
+
+#include <ESP8266WiFi.h>
+#include <WiFiClient.h>
+#include <ESP8266WebServer.h>
+#include <ESP8266mDNS.h>
+#include <ESP8266HTTPUpdateServer.h>
+
+const char* host = "esp8266-webupdate";
+const char* update_path = "/firmware";
+const char* update_username = "admin";
+const char* update_password = "admin";
+const char* ssid = "........";
+const char* password = "........";
+
+ESP8266WebServer httpServer(80);
+ESP8266HTTPUpdateServer httpUpdater;
+
+void setup(void){
+
+  Serial.begin(115200);
+  Serial.println();
+  Serial.println("Booting Sketch...");
+  WiFi.mode(WIFI_AP_STA);
+  WiFi.begin(ssid, password);
+
+  while(WiFi.waitForConnectResult() != WL_CONNECTED){
+    WiFi.begin(ssid, password);
+    Serial.println("WiFi failed, retrying.");
+  }
+
+  MDNS.begin(host);
+
+  httpUpdater.setup(&httpServer, update_path, update_username, update_password);
+  httpServer.begin();
+
+  MDNS.addService("http", "tcp", 80);
+  Serial.printf("HTTPUpdateServer ready! Open http://%s.local%s in your browser and login with username '%s' and password '%s'\n", host, update_path, update_username, update_password);
+}
+
+void loop(void){
+  httpServer.handleClient();
+}