GPL License Exceptions

Code in the repository:

- The SX1278FSK library (src/SX1278FSK.cpp) is based on
   https://github.com/pdelmo/lora_shield_arduino.git
  and licensed under 
   GNU Lesser General Public License, version 2.1 (SPDX short identifier: LGPL-2.1)

- General purpose Reed-Solomon decoder for 8-bit symbols or less
  Copyright 2003 Phil Karn, KA9Q
  May be used under the terms of the GNU Lesser General Public License (LGPL) - lgpl-2.1.txt

- some of the decoder code is more or less loosly inspired by
  * oe5dxl aprs toolchain (http://oe5dxl.hamspirit.at:8025), licensed under GNU GPL (gpl-3.0.txt)
  * Zilogs RS decoder (https://github.com/rs1729/RS), licensed under GNU GPL (gpl-3.0.txt)

- Fonts in src/fonts (FreeMono*, FreeSans*, Picopixel) taken from Adafruit-GFX-Library
  licensed under BSD License
  Font src/fonts/Terminal11x16.h taken from https://github.com/Nkawu/TFT_22_ILI9225/
  licensed under GPL-3.0

External libraries used by the project:

- Espressif 32: development platform for PlatformIO
  https://github.com/platformio/platform-espressif32
  licensed under Apache-2.0 licsense - apache.txt

- U8glib library for monochrome displays, version 2
  https://github.com/olikraus/u8g2
  licensed under the new-bsd license (two-clause bsd license) - LICENSE-u8g2.txt

- MicroNMEA - A compact Arduino library to parse NMEA sentences
  https://github.com/stevemarple/MicroNMEA
  licsensed under LGPL-2.1 license - lgpl-2.1.txt

- ESPAsyncWebServer
  see https://github.com/me-no-dev/ESPAsyncWebServer/blob/master/src/ESPAsyncWebServer.h#L7-L19
  licsensed under LGPL-2.1 license - lgpl-2.1.txt

- Arduino GFX developing for various color displays
  https://github.com/moononournation/Arduino_GFX
  licensed under BSD License - LICENSE-Arduino_GFX.txt

- asynchronous MQTT client implementation
  https://github.com/dx168b/async-mqtt-client
  licensed under MIT license - LICENSE-mqtt.txt

- Time library for Arduino
  https://github.com/PaulStoffregen/Time
  licensed under LGPL-2.1 licsense - lgpl-2.1txt
