Since we link with static libstdc++ we need to tell gcc to only export
the necessary symbols.
Using "-fvisibility=hidden" will not work, since libstdc++ explicitly
exports its symbols.
In case one wants to handle openssl builds manually (or use static
libraries provided by third parties like those in Linux distros).
Note that they still must be *static* libraries, adding support for
linking against *shared* libraries needs more work (and testing).
Needs updated godot-cpp to build library with custom toolchains.
Make the OpenSSL and CMake tools more customizable letting the user
override the default platform flags via build options.
Improve dependency handling.
The num_jobs (-j flag) was being tracked as part of the cmake and
openssl build actions, thus causing a rebuild when compiling with
different concurrently.
This commit strip the -j flag from the signature of the actions so
scons won't rebuild openssl/libdatachannel when changing the parallelism
option.
Update ssl tool (now renamed openssl).
Move universal library "lipo" action to openssl tool, and add universal
builds support to cmake tool.
Add support for MSVC builds (requires nasm and perl in PATH, tested with
Strawberry Perl, VS 2019 and VS 2022).
Add support for building "macos" via OSXCross.
