Draft: [3.x] buildsystem: use CMake to build libvlc.so

And add an option to link to C++ runtime statically as in !152 (merged)

This way we can support 16K aligned C++ runtime in 3.0 with imported code from !140 (merged) adapted to using CMake.

The generated .c files are still done in the bash script, so the CMake script can't be fully integrated in gradle yet.