Add parameters on Web interface

```
#define WIFI_AP          false
#define WIFI_SSID        ""
#define WIFI_PASSWORD    ""
#define MQTT             true
#define MQTT_SERVER      "192.168.0."
#define MQTT_SERVERPORT  1883                   // use 8883 for SSL
#define MQTT_USERNAME    ""
#define MQTT_KEY         ""
```