We now have a cmake-format config file.
We no longer use list variables for sources, instead using
target_sources when we need to add, in accordance with current
best practice. (This makes it a lot easier to edit too.) There's no more
include_directories(), add_definitions(), or other gently-deprecated
directory-scoped commands, nor any CMake scripts that include
a parent directory reference (named targets instead)
The generated files should be in auxiliary/bindings/*.{c,h}. For this to work
meson.build has to be in the bindings/ subdir:
https://github.com/mesonbuild/meson/issues/2320
Move CMakeLists.txt there too for some consistency.
Also fixes the previous include hack.