* configure.ac: Activate C++17, and replace --enable-c++17 by
--enable-c++20.
* NEWS: Mention the news.
* .gitlab-ci.yml: Use C++20 for the former C++17 builds.
* HACKING, README, doc/org/compile.org, doc/org/concepts.org,
doc/org/index.org, doc/org/install.org, doc/org/tut.org,
doc/org/upgrade2.org, spot/misc/escape.hh: Adjust mentions
of C++14.
* configure.ac: Compile in C++14 by default and rename
--enable-c++14 as c++17.
* doc/org/compile.org, doc/org/concepts.org, doc/org/index.org,
doc/org/install.org, doc/org/tut.org, doc/org/upgrade2.org, HACKING,
NEWS, README: Adjust all mentions of C++11.
* spot/twaalgos/stats.hh: Use std::make_unique.
The libtool version distributed by Debian is patched to *not* propagate
dependencies (i.e., if libA depends on libB, then linking against libA
will not automatically link against libB, it has to be explicit),
contrary to what the Libtool manual document. So now we explicitly
link against both libA and libB in such case.
* configure.ac: Remove the workaround that does not work for
MinGW.
* doc/org/compile.org: Mention the issue.
* bin/Makefile.am, tests/Makefile.am, spot/ltsmin/Makefile.am,
spot/gen/Makefile.am, doc/org/g++wrap.in: Make the dependencies
explicit.
Part of #176.
* doc/org/autfilt.org, doc/org/compile.org, doc/org/concepts.org,
doc/org/csv.org, doc/org/dstar2tgba.org, doc/org/genltl.org,
doc/org/hoa.org, doc/org/install.org, doc/org/ioltl.org,
doc/org/ltl2tgba.org, doc/org/ltl2tgta.org, doc/org/ltlcross.org,
doc/org/ltldo.org, doc/org/ltlfilt.org, doc/org/ltlgrind.org,
doc/org/oaut.org, doc/org/randaut.org, doc/org/randltl.org,
doc/org/satmin.org, doc/org/tools.org, doc/org/tut.org,
doc/org/tut01.org, doc/org/tut02.org, doc/org/tut03.org,
doc/org/tut10.org, doc/org/tut20.org, doc/org/tut21.org,
doc/org/tut22.org, doc/org/tut30.org, doc/org/upgrade2.org: Here.
* doc/org/index.org: Also add keywords in case it is useful, and
use a more descripting title for search engines.
