[bug#27434] [PATCH] gnu: Add mkvtoolnix.

[Gregor Giesen <giesen@zaehlwerk.net>]

Dear Leo,

I had another look at those libraries:

On Sun, Jun 25, 2017 at 09:44:01AM -0400, Leo Famulari wrote:
> I noticed it includes some files in 'lib/', and at least some of them
> appear to be bundled copies of 3rd-party libraries:
>
> drwxr-xr-x 1 leo leo 194 May 20 13:25 libebml       -> libebml
> drwxr-xr-x 1 leo leo 236 May 20 13:25 libmatroska   -> libmatroska
> drwxr-xr-x 1 leo leo  70 May 20 13:25 nlohmann-json -> nlohmann-json-cpp
> drwxr-xr-x 1 leo leo  26 May 20 13:25 pugixml       -> pugixml
> drwxr-xr-x 1 leo leo  18 May 20 13:25 utf8-cpp      -> utfcpp
those can be removed, they are already included in ‘inputs’ and the 
configure script favours the system (guix) lib over them.

The remaining three libraries are referenced directly from the source
code. Here are comments from README.md:

> drwxr-xr-x 1 leo leo  66 May 20 13:25 boost
--8<---------------cut here---------------start------------->8---
A class, `utf8_codecvt_facet`, derived from `std::codecvt<wchar_t, char>`,
which can be used to convert utf8 data in files into `wchar_t` strings
in the application.

  * License: Boost Software License - Version 1.0 (see `doc/licenses/Boost-1.0.txt`)
  * URL: http://www.boost.org
--8<---------------cut here----------------end-------------->8---

The other two are some ancient and orphaned libraries for deprecated
video formats, however GPLv2/LGPLv2.1:

> drwxr-xr-x 1 leo leo 116 May 20 13:25 avilib-0.6.10
--8<---------------cut here---------------start------------->8---
Reading and writing avi files.

Copyright (C) 1999 Rainer Johanni <Rainer@Johanni.de>, originally part
of the transcode package.

  * License: GNU General Public License v2
  * URL: http://www.transcoding.org/

> drwxr-xr-x 1 leo leo 120 May 20 13:25 librmff
librmff is short for 'RealMedia file format access library'. It aims
at providing the programmer an easy way to read and write RealMedia
files.

  * License: GNU Lesser General Public License v2.1 (see `doc/licenses/LGPL-2.1.txt`)
  * URL: https://www.bunkus.org/videotools/librmff/index.html
--8<---------------cut here----------------end-------------->8---

Is it ok to just include them and adding those two licenses the package?

Best,
Gregor