v0.2.1 - support additional 'clean' targets using MORE_CLEAN

• 0.2.1 (2020-05-02)
  • Add MORE_CLEAN, an optional user-provided make-target to do additional
    cleaning, such as removing directories created by code-generators.

v0.2 - usable as a library, support multiple external library locations

• 0.2 (2020-03-21)
  • Mark main() as a weak reference (supported by g++ and clang++) so that
    UniHostDuino can be used as a library in programs that already provide a
    main() function. (Thanks to Max Prokhorov mcspr@).
  • Replace ARDUINO_LIB_DIR with ARDUINO_LIB_DIRS which supports
    multiple external library locations, in addition to siblings of the
    UnixHostDuino directory. The ARDUINO_LIB_DIR is no longer supported.

0.1.3 - Add installation instructions to README.md

• 0.1.3 (2019-11-21)
  • Add 'Installation' section to the README.md.
  • Add UNIX_HOST_DUINO macro symbol to the CPPFLAGS to allow conditional
    code that activates only when UnixHostDuino is used.

0.1.2 - Implement Serial.flush()

• 0.1.2 (2019-09-04)
  • Implement StdioSerial::flush() to enable Serial.flush().

0.1.1 - support usage inside continuous build

• 0.1.1 (2019-08-14)
  • If the STDIN is not a real tty, continue without putting it into raw mode
    or exiting with an error. This allows unit tests inside continuous build
    frameworks.

0.1 - initial release after renaming and splitting from AUnit/unitduino

• 0.1 (2019-07-31)
  • Split from AUnit and renamed from unitduino to UnixHostDuino.
  • Add UNIT_HOST_DUINO macro.
  • Add FPSTR() macro for compatibilty with ESP8266 and ESP32.
  • Add LED_BUILTIN macro.