RFC: struct-field visitors/reflection for lcf structs #318

I have found this library recently: https://github.com/cbeck88/visit_struct It provides structure visitors and reflection. It seems easy to add (likely just generator changes) and has a good license (boost).

• Do we have similar functionality in liblcf which could be adapted or maybe simplified with this?
• Do we want/need this? It seems not useful for Player at least, but maybe for some tools.
  For example I would like to have an lcfgrep tool and it seems easy to do with this (just iterate over every struct/member)