FIX for Arduino LEONARDO set default SPI_SC / SS (and add configureSPI)

[ricardojlrufino]

No description provided.

[ricardojlrufino]

Usage

void setup()
{
  Serial.begin(9600);

  Ethernet.setSSPIN(4,4); // Default is 10;
  Ethernet.begin(mac,myIP);

  server.begin();
}