1 - Ferduino code was reorganized to be compatible with PlatformIO. This IDE can be used with VScode or Atom.
Check here how to compile Ferduino code with Atom and PIO.
In Arduino IDE only the files "Ferduino_Aquarium_Controller.ino" and "Configuration.h" will be shown.
All others files will be hidden. In "Configuration.h" are all the basic settings for build the code.
If do you want change the functions on core you should use PIO (PlatformIO) or other code editor but Arduino IDE should be enough for the big part of Ferduino users.
2 - The Henning's library DS1307 was finally edited by me to work with Wire library.
The library now will work only with pins 20 and 21 (SDA and SCL).
The library should be compatible with multiple devices on I2C BUS.
In others words won't have conflict with external EEPROM or PCF8575. Also the library was renamed to "RTC_DS.h".
Ferduino Mega's owners should move RTC jumpers for the position 2-3 to make RTC work.
3 - As the pins 18 and 19 (Serial1) now are free it will be used for WiFi module.
Hardware serial should be more reliable and fast than software serial with "NeoSWSerial.h". For this reason baud rate was changed to 38400 again.
4 - PCF8575 will be REQUIRED for default code so if you don't want change code core by yourself you should buy this module.
5 - SdFat library was updated and should solve some problems of conflict with W5100.
6 - Ethernet library was changed to 2.0 version from Paul Stoffregen that should be released with Arduino IDE on future. This library supports custom SS by default.