add a simple TCP example

libraries/ESP8266WiFi/examples/WiFiClientMin/WiFiClientMin.ino

@@ -0,0 +1,68 @@
+/*
+ *  This sketch sends a message to a TCP server
+ *
+ */
+
+#include <ESP8266WiFi.h>
+#include <ESP8266WiFiMulti.h>
+
+ESP8266WiFiMulti WiFiMulti;
+
+void setup() {
+    Serial.begin(115200);
+    delay(10);
+
+    // We start by connecting to a WiFi network
+    WiFiMulti.addAP("SSID", "passpasspass");
+
+    Serial.println();
+    Serial.println();
+    Serial.print("Wait for WiFi... ");
+
+    while(WiFiMulti.run() != WL_CONNECTED) {
+        Serial.print(".");
+        delay(500);
+    }
+
+    Serial.println("");
+    Serial.println("WiFi connected");
+    Serial.println("IP address: ");
+    Serial.println(WiFi.localIP());
+
+    delay(500);
+}
+
+
+void loop() {
+    const uint16_t port = 80;
+    const char * host = "192.168.1.1"; // ip or dns
+
+	
+	
+    Serial.print("connecting to ");
+    Serial.println(host);
+
+    // Use WiFiClient class to create TCP connections
+    WiFiClient client;
+
+    if (!client.connect(host, port)) {
+        Serial.println("connection failed");
+		Serial.println("wait 5 sec...");
+		delay(5000);
+        return;
+    }
+
+    // This will send the request to the server
+    client.print("Send this data to server");
+
+    //read back one line from server
+    String line = client.readStringUntil('\r');
+    client.println(line);
+
+    Serial.println("closing connection");
+    client.stop();
+	
+    Serial.println("wait 5 sec...");
+	delay(5000);
+}
+