Log Message:
libmicrohttpd: update to 0.9.73.

Sun 25 Apr 2021 14:00:00 MSK
Released GNU libmicrohttpd 0.9.73

    This release brings new features, improvements, and a few fixes.
    The most important addition is the new function for vector-backed
    responses, based on the patch contributed by NASA engineers.
    Other changes include compatibility with autoconf 2.70+, improved
    testsuite compatibility with CI systems, fixed and improved MSVC
    builds, and implemention of ALPN support.

    More detailed list of notable changes:

    API changes:
    + Added new function MHD_create_response_from_iovec(), based on the
      patch provided by Lawrence Sebald and Damon N. Earp from NASA.
    + Added MHD_OPTION_SIGPIPE_HANDLED_BY_APP daemon option.
    + Added new function MHD_run_wait().
    + Added MHD_OPTION_TLS_NO_ALPN to disable usage of ALPN even if
      it is supported by TLS library.

    New features:
    + Added '--enable-heavy-tests' configure parameter (disabled by
      default).
    + Implemented support for ALPN.

    Improvements and enhancements:
    * Return timeout of zero also for connections awaiting cleanup.
    * Compatibility with autoconf >=2.70, used new autoconf features.
    * Warn user when custom logger option is not the first option.
    * Added information to the header about minimal MHD version when
      particular symbols were introduced.
    * Updated test certificates to be compatible with modern browsers.
    * Added on-fly detection of UNIX domain sockets and pipes, MHD does
      not try to use TCP/IP-specific socket options on them.
    * Report more detailed error description in the MHD log for send
      and receive errors.
    * Enabled bind port autodetection for MSVC builds.

    Fixes:
    # Fix PostProcessor to always properly stop iteration when
      application callback tells it to do so.
    # Fixed MD5 digest authorization broken when compiled without
      variable length arrays support (notably with MSVC).
    # Fixed detection of type of send errors on W32.

    -- Evgeny Grin (Karlson2k)