this updates the version-sync script to generate proper SO versions
which will be used by cmake and libtool to create version symlinks
on the system when a library is installed as well as setting the SO
version in the binary.
To see what this does, you have to configure tox with a prefix:
./configure --prefix=/tmp/tox-with-libtool
mkdir cbuild && cd cbuild && cmake -DCMAKE_INSTALL_PREFIX=/tmp/tox-with-cmake ..
Then run `make && make install`.
in both instances you should see the following installed in `lib/`:
libtoxcore.so -> libtoxcore.so.1.4.0
libtoxcore.so.1 -> libtoxcore.so.1.4.0
libtoxcore.so.1.4.0
inside the binary the soname should be the one with .1 and it should not
contain the full version:
$ objdump -p libtoxcore.so.1.4.0 | grep SONAME
SONAME libtoxcore.so.1
We disable the ones that fire, so we can use -Werror. We can then
investigate each warning individually and see whether to fix it or to
keep silencing it.
Compiling as C++ changes nothing semantically, but ensures that we don't
break C++ compatibility while also retaining C compatibility.
C++ compatibility is useful for tooling and additional diagnostics and
analyses.
It is still C code, so still compatible with C compilers as well. This
change lets us see more clearly where implicit conversions occur by
making them explicit.
