Log Message:
expat: update to 2.2.10.

Use cmake for building.

Release 2.2.10 Sat October 3 2020
        Bug fixes:
  #390 #395 #398  Fix undefined behavior during parsing caused by
                    pointer arithmetic with NULL pointers
       #404 #405  Fix reading uninitialized variable during parsing
            #406  xmlwf: Add missing check for malloc NULL return

        Other changes:
            #396  Windows: Drop support for Visual Studio <=8.0/2005
            #409  Windows: Add missing file "Changes" to the installer
                    to fix compilation with CMake from installed sources
            #403  xmlwf: Document exit codes in xmlwf manpage and
                    exit with code 3 (rather than code 1) for output errors
                    when used with "-d DIRECTORY"
       #356 #359  MinGW: Provide declaration of rand_s for mingwrt <5.3.0
       #383 #392  Autotools: Use -Werror while configure tests the compiler
                    for supported compile flags to avoid false positives
  #383 #393 #394  Autotools: Improve handling of user (C|CPP|CXX|LD)FLAGS,
                    e.g. ensure that they have the last word over flags added
                    while running ./configure
            #360  CMake: Create libexpatw.{dll,so} and expatw.pc (with emphasis
                    on suffix "w") with -DEXPAT_CHAR_TYPE=(ushort|wchar_t)
            #360  CMake: Detect and deny unsupported build combinations
                    involving -DEXPAT_CHAR_TYPE=(ushort|wchar_t)
            #360  CMake: Install pre-compiled shipped xmlwf.1 manpage in case
                    of -DEXPAT_BUILD_DOCS=OFF
  #375 #380 #419  CMake: Fix use of Expat by means of add_subdirectory
       #407 #408  CMake: Keep expat target name constant at "expat"
                    (i.e. refrain from using the target name to control
                    build artifact filenames)
            #385  CMake: Fix compilation with -DEXPAT_SHARED_LIBS=OFF for
                    Windows
                  CMake: Expose man page compilation as target \ 
"xmlwf-manpage"
       #413 #414  CMake: Introduce option EXPAT_BUILD_PKGCONFIG
                    to control generation of pkg-config file "expat.pc"
            #424  CMake: Add minimalistic support for building binary packages
                    with CMake target "package"; based on CPack
            #366  CMake: Add option -DEXPAT_OSSFUZZ_BUILD=(ON|OFF) with
                    default OFF to build fuzzer code against OSS-Fuzz and
                    related environment variable LIB_FUZZING_ENGINE
            #354  Fix testsuite for -DEXPAT_DTD=OFF and -DEXPAT_NS=OFF, each
    #354 #355 ..
       #356 #412  Address compiler warnings
       #368 #369  Address pngcheck warnings with doc/*.png images
                  Version info bumped from 7:11:6 to 7:12:6

        Special thanks to:
            asavah
            Ben Wagner
            Bhargava Shastry
            Frank Landgraf
            Jeffrey Walton
            Joe Orton
            Kleber Tarcísio
            Ma Lin
            Maciej Sroczyński
            Mohammed Khajapasha
            Vadim Zeitlin
                 and
            Cppcheck 2.0 and the Cppcheck team