v1.8.0 to add support to ESP8266 using W5x00

### Releases v1.8.0

1. Add support to ESP8266 using W5x00 with [**lwIP_w5100**](https://github.com/esp8266/Arduino/tree/master/libraries/lwIP_w5100) or [**lwIP_w5500**](https://github.com/esp8266/Arduino/tree/master/libraries/lwIP_w5500) library
2. Add example [AsyncHTTPRequest_ESP8266_Ethernet](https://github.com/khoih-prog/AsyncHTTPRequest_Generic/tree/master/examples/AsyncHTTPRequest_ESP8266_Ethernet) to demo the new feature.
3. Update `Packages' Patches`

examples/AsyncHTTPRequest_ESP8266_Ethernet/AsyncHTTPRequest_ESP8266_Ethernet.ino

@@ -0,0 +1,233 @@
+/****************************************************************************************************************************
+  AsyncHTTPRequest_ESP.ino - Dead simple AsyncHTTPRequest for ESP8266, ESP32 and currently STM32 with built-in LAN8742A Ethernet
+  
+  For ESP8266, ESP32 and STM32 with built-in LAN8742A Ethernet (Nucleo-144, DISCOVERY, etc)
+  
+  AsyncHTTPRequest_Generic is a library for the ESP8266, ESP32 and currently STM32 run built-in Ethernet WebServer
+  
+  Based on and modified from asyncHTTPrequest Library (https://github.com/boblemaire/asyncHTTPrequest)
+  
+  Built by Khoi Hoang https://github.com/khoih-prog/AsyncHTTPRequest_Generic
+  Licensed under MIT license
+  
+  Copyright (C) <2018>  <Bob Lemaire, IoTaWatt, Inc.>
+  This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License 
+  as published bythe Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+  You should have received a copy of the GNU General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.  
+ *****************************************************************************************************************************/
+//************************************************************************************************************
+//
+// There are scores of ways to use AsyncHTTPRequest.  The important thing to keep in mind is that
+// it is asynchronous and just like in JavaScript, everything is event driven.  You will have some
+// reason to initiate an asynchronous HTTP request in your program, but then sending the request
+// headers and payload, gathering the response headers and any payload, and processing
+// of that response, can (and probably should) all be done asynchronously.
+//
+// In this example, a Ticker function is setup to fire every 300 seconds to initiate a request.
+// Everything is handled in AsyncHTTPRequest without blocking.
+// The callback onReadyStateChange is made progressively and like most JS scripts, we look for
+// readyState == 4 (complete) here.  At that time the response is retrieved and printed.
+//
+// Note that there is no code in loop().  A code entered into loop would run oblivious to
+// the ongoing HTTP requests.  The Ticker could be removed and periodic calls to sendRequest()
+// could be made in loop(), resulting in the same asynchronous handling.
+//
+// For demo purposes, debug is turned on for handling of the first request.  These are the
+// events that are being handled in AsyncHTTPRequest.  They all begin with Debug(nnn) where
+// nnn is the elapsed time in milliseconds since the transaction was started.
+//
+//*************************************************************************************************************
+
+#if !( defined(ESP8266) )
+  #error This code is intended to run on the ESP8266 platform! Please check your Tools->Board setting.
+#endif
+
+// Level from 0-4
+#define ASYNC_HTTP_DEBUG_PORT     Serial
+#define _ASYNC_HTTP_LOGLEVEL_     1    
+
+// 300s = 5 minutes to not flooding
+#define HTTP_REQUEST_INTERVAL     60  //300
+
+// 10s
+#define HEARTBEAT_INTERVAL        10
+
+//////////////////////////////////////////////////////////
+
+#define USING_W5500         true
+#define USING_W5100         false
+#define USING_ENC28J60      false
+
+#include <SPI.h>
+
+#define CSPIN       16      // 5
+
+#if USING_W5500
+  #include "W5500lwIP.h"
+  #define SHIELD_TYPE       "ESP8266_W5500 Ethernet"
+  
+  Wiznet5500lwIP eth(CSPIN); 
+   
+#elif USING_W5100
+  #include <W5100lwIP.h>
+  #define SHIELD_TYPE       "ESP8266_W5100 Ethernet"
+  
+  Wiznet5100lwIP eth(CSPIN);
+
+#elif USING_ENC28J60
+  #include <ENC28J60lwIP.h>
+  #define SHIELD_TYPE       "ESP8266_ENC28J60 Ethernet"
+  
+  ENC28J60lwIP eth(CSPIN);
+#else
+  // default if none selected
+  #include "W5500lwIP.h"
+
+  Wiznet5500lwIP eth(CSPIN);
+#endif
+
+
+#include <WiFiClient.h> // WiFiClient (-> TCPClient)
+
+using TCPClient = WiFiClient;
+
+
+
+
+
+//////////////////////////////////////////////////////////
+
+#define ASYNC_HTTP_REQUEST_GENERIC_VERSION_MIN_TARGET      "AsyncHTTPRequest_Generic v1.7.1"
+#define ASYNC_HTTP_REQUEST_GENERIC_VERSION_MIN             1007001
+
+// To be included only in main(), .ino with setup() to avoid `Multiple Definitions` Linker Error
+#include <AsyncHTTPRequest_Generic.h>             // https://github.com/khoih-prog/AsyncHTTPRequest_Generic
+
+#include <Ticker.h>
+
+AsyncHTTPRequest request;
+Ticker ticker;
+Ticker ticker1;
+
+void heartBeatPrint()
+{
+  static int num = 1;
+
+  if (eth.connected())
+    Serial.print(F("H"));        // H means connected to Ethernet
+  else
+    Serial.print(F("F"));        // F means not connected to Ethernet
+
+  if (num == 80)
+  {
+    Serial.println();
+    num = 1;
+  }
+  else if (num++ % 10 == 0)
+  {
+    Serial.print(F(" "));
+  }
+}
+
+void sendRequest() 
+{
+  static bool requestOpenResult;
+  
+  if (request.readyState() == readyStateUnsent || request.readyState() == readyStateDone)
+  {
+    //requestOpenResult = request.open("GET", "http://worldtimeapi.org/api/timezone/Europe/London.txt");
+    requestOpenResult = request.open("GET", "http://worldtimeapi.org/api/timezone/America/Toronto.txt");
+    
+    if (requestOpenResult)
+    {
+      // Only send() if open() returns true, or crash
+      request.send();
+    }
+    else
+    {
+      Serial.println(F("Can't send bad request"));
+    }
+  }
+  else
+  {
+    Serial.println(F("Can't send request"));
+  }
+}
+
+void requestCB(void* optParm, AsyncHTTPRequest* request, int readyState) 
+{
+  (void) optParm;
+  
+  if (readyState == readyStateDone) 
+  {
+    Serial.println(F("\n**************************************"));
+    Serial.println(request->responseText());
+    Serial.println(F("**************************************"));
+    
+    request->setDebug(false);
+  }
+}
+
+void initEthernet()
+{
+  SPI.begin();
+  SPI.setClockDivider(SPI_CLOCK_DIV4);
+  SPI.setBitOrder(MSBFIRST);
+  SPI.setDataMode(SPI_MODE0);
+  eth.setDefault();
+  
+  if (!eth.begin()) 
+  {
+    Serial.println("No Ethernet hardware ... Stop here");
+    
+    while (true) 
+    {
+      delay(1000);
+    }
+  } 
+  else 
+  {
+    Serial.print("Connecting to network : ");
+    
+    while (!eth.connected()) 
+    {
+      Serial.print(".");
+      delay(1000);
+    }
+  }
+  
+  Serial.println();
+  Serial.print("Ethernet IP address: ");
+  Serial.println(eth.localIP());
+}
+
+void setup()
+{
+  // put your setup code here, to run once:
+  Serial.begin(115200);
+  while (!Serial && millis() < 5000);
+
+  delay(200);
+  
+  Serial.print(F("\nStarting AsyncHTTPRequest_ESP8266_Ethernet on ")); Serial.print(ARDUINO_BOARD);
+  Serial.print(F(" using ")); Serial.println(SHIELD_TYPE);
+  Serial.println(ASYNC_HTTP_REQUEST_GENERIC_VERSION);
+
+  initEthernet();
+
+  request.setDebug(false);
+  
+  request.onReadyStateChange(requestCB);
+  ticker.attach(HTTP_REQUEST_INTERVAL, sendRequest);
+
+  ticker1.attach(HEARTBEAT_INTERVAL, heartBeatPrint);
+  
+  // Send first request now
+  sendRequest();  
+}
+
+void loop()
+{ 
+}