Automatic Binding Generator using Doxygen, Python, and Sol3

Use with this branch of U3D: https://github.com/SirNate0/U3D/tree/lua-bindings

1. Build that U3D branch. The samples and player will fail to build, as the binding function is left undefined.
2. Build this project, pointing it at the library that was just built as URHO3D_HOME. This project defines the binding function.
3. You will need to symlink the bin/Data folder into the Build/bin folder, as it needs a few of the changed files. I think Urho's CMake code handles this automatically.
4. The Build/bin/test-sol3 executable should run without crashing. However, it's not possible to interact with it, as event subscriptions are not finished at present (hence the function at the start of bin/Data/run.lua that just prints a TODO.

To rebuild the bindings

1. Navigate to the generator folder
2. Run doxygen Doxyfile. You will need to edit the Doxyfile to point at your U3D installation first.

• You may need to run it a couple times or remove the generated-xml contents first, I've had some issues in the past where it looked like it was using old content (I may have been mistaken, but I thought I should mention the possibility).

3. Run generate-bindings.py. You will probably have to install a few packages for this.

• This removes the generator/generated folder and recreates it (this way old no-longer-existing files are removed and don't stick around).
• To prevent make from thinking this means all of the generated files change every time, the python code then selectively updates the generator/synced-generated files based on actual changes.
• This generator/synced-generated folder is what make is building, symlinked into the outer project folder as generated. This avoids the unnecessary extra rebuilding, without needing something like CCache.

4. Rebuild