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)
This allows transitive dependencies to work easier and improves compatibility.
It takes a little bit more storage at build time, and possibly a little extra time.