NDO_AUTO_ISO14443_4 is now set to _true_ by default with nfc_target_init();
nfc_emulate_target() now fails (return _false_) when emulator->state_machine->io() failed;
Initialize nfc_device_t variables to _false_ in order to send correctly (see notes in nfc-device.c);
nfc_emulate_forum_tag4 prints error when nfc_emulate_target() failed.