/**

@page license License

Libxlsxwriter is released under a FreeBSD license:

    Copyright 2014-2021, John McNamara <jmcnamara@cpan.org>
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:

    1. Redistributions of source code must retain the above copyright notice,
       this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
    IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
    THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    The views and conclusions contained in the software and documentation are
    those of the authors and should not be interpreted as representing
    official policies, either expressed or implied, of the FreeBSD Project.


Libxlsxwriter includes `queue.h` and `tree.h` from FreeBSD, the `minizip`
component of `zlib`. It also includes and uses the optional `tmpfileplus`,
`md5` and `emyg_dtoa`. These components which have the following licenses:


Queue.h from FreeBSD:

    Copyright (c) 1991, 1993
     The Regents of the University of California.  All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:
    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.
    4. Neither the name of the University nor the names of its contributors
       may be used to endorse or promote products derived from this software
       without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    SUCH DAMAGE.


Tree.h from FreeBSD:

    Copyright 2002 Niels Provos <provos@citi.umich.edu>
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:
    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.

    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
    OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
    IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
    NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
    THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


The `minizip` files used in the libxlsxwriter source tree are taken from the
`zlib` ` contrib/minizip` directory. [Zlib](http://www.zlib.net) has the
following License/Copyright:

    (C) 1995-2013 Jean-loup Gailly and Mark Adler

    This software is provided 'as-is', without any express or implied
    warranty.  In no event will the authors be held liable for any damages
    arising from the use of this software.

    Permission is granted to anyone to use this software for any purpose,
    including commercial applications, and to alter it and redistribute it
    freely, subject to the following restrictions:

    1. The origin of this software must not be misrepresented; you must not
       claim that you wrote the original software. If you use this software
       in a product, an acknowledgment in the product documentation would be
       appreciated but is not required.
    2. Altered source versions must be plainly marked as such, and must not be
       misrepresented as being the original software.
    3. This notice may not be removed or altered from any source distribution.

    Jean-loup Gailly        Mark Adler
    jloup@gzip.org          madler@alumni.caltech.edu

The `minizip` files have the following additional copyright declarations:

    Copyright (C) 1998-2010 Gilles Vollant
    (minizip) ( http://www.winimage.com/zLibDll/minizip.html )

    Modifications for Zip64 support
    Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )

Note, it is possible to compile libxlsxwriter without statically linking the
`minizip` files and instead dynamically linking to `lminizip`, see
@ref gsg_minizip.

[Tmpfileplus](http://www.di-mgt.com.au/c_function_to_create_temp_file.html)
has the following license:

    This Source Code Form is subject to the terms of the Mozilla Public
    License, v. 2.0. If a copy of the MPL was not distributed with this
    file, You can obtain one at http://mozilla.org/MPL/2.0/.

    Copyright (c) 2012-16 David Ireland, DI Management Services Pty Ltd
    <http://www.di-mgt.com.au/contact/>.

See the [Mozilla Public License, v. 2.0](http://mozilla.org/MPL/2.0/).

Note, it is possible to compile libxlsxwriter using the standard library
`tmpfile()` function instead of `tmpfileplus`, see @ref gsg_tmpdir.

The [Milo Yip DTOA library](https://github.com/miloyip/dtoa-benchmark) for
converting doubles to strings. It has the following license:

    Copyright (C) 2015 Doug Currie
    based on dtoa_milo.h
    Copyright (C) 2014 Milo Yip

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    THE SOFTWARE.

This Milo Yip DTOA library (emyg_dtoa) is uses to avoid issues where the
standard sprintf() dtoa function changes output based on locale settings. It
is also 40-50% faster than the standard dtoa for raw numeric data. The use of
this library is optional. If you wish to use it you can pass
`USE_DTOA_LIBRARY=1` to make when compiling.

[Openwall MD5](https://openwall.info/wiki/people/solar/software/public-domain-source-code/md5)
has the following licence:

    This software was written by Alexander Peslyak in 2001.  No copyright is
    claimed, and the software is hereby placed in the public domain.
    In case this attempt to disclaim copyright and place the software in the
    public domain is deemed null and void, then the software is
    Copyright (c) 2001 Alexander Peslyak and it is hereby released to the
    general public under the following terms:

    Redistribution and use in source and binary forms, with or without
    modification, are permitted.

    There's ABSOLUTELY NO WARRANTY, express or implied.

    (This is a heavily cut-down "BSD license".)

Note, the MD5 library is used to avoid including duplicate image files in the
xlsx file. If you don't want to use this code, and the additional licence, you
can use OpenSSL's MD5 functions instead by passing `USE_OPENSSL_MD5=1` to
make. If this functionality isn't required it is possible to compile
libxlsxwriter without image deduplication by passing `USE_NO_MD5=1` to make.

See also @ref gsg_md5.

Next: @ref changes
*/
