* Work out what module filenames should be in CMake, and give those to C++
* Compare just the module filenames instead of the full strings
* Deal with OSG trying to support both UTF-8 and system-eight-bit-code-page file paths on Windows.
* Add a comment complaining about the constexpr situation.
* Use a stub implementation when using static OSG - apparently we don't actually support mixing and matching static and dynamic OSG plugins even though OSG itself does.