Add support to STM32

Manage support for STM32, soon the tutorial on www.mischianti.org

Fix ethernet constructor, styling files structure

Fix ethernet constructor, styling files structure

Fix anonymous constructor and SPIFFS

Fix anonymous constructor and SPIFFS

Add anonymous user management and follow RFC for LIST command

Add anonymous user management
ftpSrv.begin();

and follow RFC for LIST command.
The file list now have this pattern
-rw------- 1 peter 848 Dec 14 11:22 00README.txt

ESP32 v2 core LittleFS management, add end and setLocalIP method, fix

Arduino ESP32 v2 core LittleFS management with the core library.
Add end method to stop the service and set setLocalIP method to set the IP manually.
Some minor fix to manage delayed WiFi activation.

SimpleFTPServer minor fix

Fix the LIST command problem.

Upgraded release with all esp32 and esp8266 native filesystem and some kind of SD for Arduino

Upgraded release with all esp32 and esp8266 native filesystem and some kind of SD for Arduino.
Simple FTP Server for

esp8266 (Flash: SPIFFs, LittleFS. SD: SD, SdFat 2)
esp32 (SPIFFS, LITTLEFS, FFAT, SdFat)
Arduino (SD with 8.3 file format, SdFat 2)
Wio Terminal (SdFat 2, and native FAT)

Not already tested but supported external SPI memory with Arduino, Arduino MKR and esp
Not already tested SD with Arduino MKR

First stable and tested release.

Simple FTP server for esp8266 (SPIFFS and LittleFS), esp32 (SPIFFS) and Arduino (SD basic lib with 8.3 file format)