better compatibility for IPAddress changes with external libraries (#5438)

Author: d-a-v

Diff for: cores/esp8266/IPAddress.h

@@ -41,7 +41,7 @@
 #else // lwIP-v2+
 #define CONST const
 #if !LWIP_IPV6
-#define ip_addr ipv4_addr
+struct ip_addr: ipv4_addr { };
 #endif // !LWIP_IPV6
 #endif // lwIP-v2+
 
@@ -208,6 +208,4 @@ class IPAddress: public Printable {
 extern CONST IPAddress INADDR_ANY;
 extern const IPAddress INADDR_NONE;
 
-#include <AddrList.h>  // bring interface iterator
-
 #endif

Diff for: libraries/ESP8266WiFi/examples/EarlyDisableWiFi/EarlyDisableWiFi.ino

@@ -1,5 +1,6 @@
 
 #include <ESP8266WiFi.h>
+#include <AddrList.h>
 
 #ifndef STASSID
 #define STASSID "your-ssid"

Diff for: libraries/ESP8266WiFi/examples/IPv6/IPv6.ino

@@ -19,6 +19,7 @@
 #include <ESP8266WiFi.h>
 #include <WiFiUdp.h>
 #include <PolledTimeout.h>
+#include <AddrList.h>
 #include <lwip/dns.h>
 
 #ifndef STASSID