Added support of Arduino GIGA WiFi.
Section MBED microcontrollers.
`
// Arduino MBED microcontrollers configuration LIKE Arduino GIGA
#ifndef DEFAULT_EMAIL_NETWORK_TYPE_ARDUINO_MBED
#define DEFAULT_EMAIL_NETWORK_TYPE_MBED NETWORK_MBED_WIFI
#define DEFAULT_INTERNAL_ARDUINO_MBED_STORAGE STORAGE_NONE
#define DEFAULT_EXTERNAL_ARDUINO_MBED_STORAGE STORAGE_SD
#endif
`