ReleaseNotes

        and '}'.
      - libc/unisted:  Change brings strtol() and related functions more
        conformant with POSIX.  Corner cases like strtol(-2147483648, NULL,
        10) now pass clang -fsanitize=integer without warnings.  From Juha
        Niskanen.
      - libc/unistd: sleep() was returning remaining nanoseconds (kind of),
        instead the remaining seconds.  From Eunbong Song.
      - termios.h:  Fix CRTSCTS define to include input and output flow. From
        Lorenz Meier.

    * Build/Configuration System:

      - configs/*/defconfig: The buttons example was changed to archbuttons.
        As a result all of the button configurations are broken and need some
        renaming in the defconfig files.  Noted by Frank Berkert.
      - config/*/defconfgs: More fallout from name change of
        apps/examples/buttons to archbuttons.
      - configs:  All QE encoder files.  Last change made timer hard-coded to
        3. Make configurable.
      - configs: Remove all traces of the no-longer existent ARCHBUTTONS
        example.  Remove all button configurations that depended on the
        obsoleted ARCHBUTTON example.
      - minnsh Configurations:  Remove minnsh configurations and support
        logic:  up_getc() and lowinstream.  This was an interesting exercise
        to see just how small you could get NuttX, but otherwise it was not
        useful:  (1) the NSH code violated the OS interface layer by callup
        up_getc() and up_putc() directly, and (2) while waiting for character
        input, NSH would call up_getc() which would hog all of the CPU.  Not a
        reasonable solution other than as a proof of concept.

    * Application Build/Configuration System:

      - Make.defs:  Using wrong link script if native window tool used with
        Cygwin.

    * apps/platform:

      - ESP32 Core v2 Platform: Fix some naming that prevented building the
        C++ support.

    * apps/nshlib:

      - NSH Library:  nsh_getdirpath(), use snprint instead of sprintf to
        avoid possibility of buffer overrun.  Noted by Chung Hwan Kim.

    * apps/system:

      - Remove std_readline().  This called up_getc() and up_putc() directly,
        violating the POSIX OS interface.

    * apps/netutils:

      - FTPD: Fixed bug that didn't free ftpd ressources on exit.  From Pascal
        Speck.
      - NTP client: Fix missing left parenthesis.  From Pierre-Noel Bouteville.
      - cJSON: Import patch to fix:cJSON_PrintUnformatted() behaves unexpected
        if an empty array shall be printed to text. from Jerome Lang
        2012-04-19. From Pierre-Noel Bouteville.
      - esp8266 update cosmetic and many bug fix.  From Pierre-Noel Bouteville.
      - FTPD:  Fix bug un ftpd file or socket may be not closed.  From
        Pierre-Noel Bouteville.

    * apps/modbus:

      - Modbus Master is missing many files and doesn't compile at all. More
        details in
        https://groups.yahoo.com/neo/groups/nuttx/conversations/topics/13734.
        From Vytautas Lukenskas.

    * apps/examples:

      - The examples/qencoder app was trying to init the encoder by a direct
        call into the board, cheating in a local header to declare the
        normally unavailable function prototype.  From Sebastien Lorquet.
      - apps/examples/timer: Should detach signal handler before exiting.
      - examples/qencode: The examples/qencoder app was trying to init the
        encoder by a direct call into the board, cheating in a local header to
        declare the normally unavailable function prototype.  From Sebastien
        Lorquet.
      - apps/examples/archbuttons:  Removed becaue it violates OS interface
        principles.
      - examples/adc, pwm, can: Remove all usage of BOARDIOC_ADCTEST_SETUP,
        BIOARDIOC_PWMSETUP.  Remove BOARDIOC_CAN_INITIALIZE.  CAN
        initialization is now done in the board initialization logic just like
        every other device driver.
      - examples/ostest: Add some delays to the pthread cancellation test.
        With deferred cancellation enabled, things happen more asynchronously.