AltSoftSerial support

[Vido]

#include <AltSoftSerial.h>
#include "ESP8266.h"

AltSoftSerial altSerial;
ESP8266 wifi(altSerial);

void setup() {
  Serial.begin(115200);
  altSerial.begin(115200);
}

void loop() {
  String ver = wifi.getVersion();
  Serial.println(ver);
}