V4.0.0

New feature : logger can connect to multiple outputs, eg Serial, network (mqtt), file (SD card, SPIFFS)

V2

• V2.1.0 11-11-2020 : Added the concept of a stack for loggingLevels (currently fixed to 4 elements depth). This allows you to temporarily change the loggingLevel and afterwards return to the previous level with simple push pop operation
• V2.2.0 05-12-2020 : Added output to std::cout when compiled for Win32 io Arduino target