For issue #512
* README: Update instructions.
* configure.ac: Add some code to warn if Python files will be
installed in a place that is not searched up by default. Add
--with-pythondir support.
* NEWS: Mention --with-pythondir.
* NEWS, README, doc/org/compile.org: Mention the option and
its effect on compilation requirements.
* configure.ac: Add the --enable-pthread option, and ENABLE_PTHREAD
macro.
* doc/org/g++wrap.in, spot/Makefile.am, spot/libspot.pc.in: Compile
with -pthread conditionally.
* spot/graph/graph.hh, spot/twa/twagraph.cc: Adjust the code to not
use thread-local variables, and let the pthread code be optional.
* .gitlab-ci.yml: Activate --enable-pthread in two configurations.
do them using C++17's __has_include instead
* configure.ac: Do not check for sys/times.h,
valgrind/memcheck.h, and spawn.h.
* bin/common_trans.cc, spot/misc/fixpool.hh, spot/misc/mspool.hh,
spot/misc/timer.hh: Adjust to use __has_include instead.
Reported by Yuri Victorovich, on FreeBSD.
* configure.ac: Test for them.
* spot/mc/mc_instanciator.hh: Only use them if they are present.
* NEWS: Mention the fix.
Part of #447.
* configure.ac, m4/debug.m4, m4/devel.m4, m4/gccoptim.m4,
m4/ndebug.m4: Replace AC_ERROR and AC_HELP_STRING by
by AC_MSG_ERROR and AS_HELP_STRING.
Part of issue #447.
Autoconf 2.69 was released in 2012, so it now widely available. The
recent release of 2.70 is obsoleting some constructs, so it will be
easier on us if we do not have too many versions to support.
* HACKING, configure.ac: Require Autoconf 2.69.
Part of #447.
* configure.ac, m4/debug.m4, m4/devel.m4, m4/gccoptim.m4,
m4/ndebug.m4: Replace AC_ERROR and AC_HELP_STRING by
by AC_MSG_ERROR and AS_HELP_STRING.
Part of issue #447.
Autoconf 2.69 was released in 2012, so it now widely available. The
recent release of 2.70 is obsoleting some constructs, so it will be
easier on us if we do not have too many versions to support.
* HACKING, configure.ac: Require Autoconf 2.69.
* configure.ac: Call CHECK_ATOMIC after setting the C++ options.
This is probably not necessary, but it makes more sense.
* m4/l_atomic.m4: Augment the test body with a scenario
that actually requires -latomic.
