Embed light compilation parameters

[dsvensson]

For runtime/realtime lighting, or just simply community relighting, of parts or all the light and general "humm what did I now compile with" documentation, it would be very convenient if the light parameters passed on command line were embedded into the map as for example a BSPX lump automatically if -bspxhdr or -bspxlit were used, or perhaps always as bsp tools in this repository can read them, and they are harmless to engines that haven't added BSPX yet.

[dsvensson]

An probably much better alternative to this would be to rewrite the bsp embedded worldspawn as I think all command-line parameters do have worldspawn counterparts. So if a map were to be compiled with -bounce 5 and .map worldspawn has _bounce 1, or not even declared, then the bsp file worldspawn would get _bounce 5. This would mean that any future recompilation with improved tooling would start off from the same expectations the released map was compiled with.