I implemented the feature Eryk was asking for, as it's also by far the easiest way to test the add_dll_directory function. So now ctypes.CDLL (and subclasses) have a `winmode` argument that gets turned directly into LoadLibraryEx flags (changing `mode` would have required a deprecation period, as it's explicitly documented as being ignored on Windows).
I believe the docs are updated as much as necessary, but if I missed something please call out.
There are no specific "import" tests, because it's such a pain to set those up (I need to delete files from the build directory during the test, and if other tests have already used them that will fail, or I need to copy the Python install elsewhere so it doesn't pick those up). But with ctypes I can exclude the application directory from the search paths. Open to brilliant ideas here.