Several changes. I took away operator() for the proxy type, because it'd interfere with the `Callable` type and all. Alas, good things do die I suppose. =[
But! I left it on the `sol::function` type, because it's necessary to discard returns. The .call is still there, though, just incase you need it. <3
reverse_indices_builder is also there, to make sure we can push and pop without the lua api taking our types and breaking them for the std::tuple returns.
All is at it should be~