Removed files that are deprecated now that the transition to Lua scripting is more mature.
Created a version of return_stl_iterator policy that works with shared pointers to container objects. This was to fix an issue where returning a container from a function would break because the container would go out of scope and the iterators would point to invalid memory. With this version you can return a shared_ptr to a container and keep a reference so it doesn't go out of scope. Having both versions of the return_stl_iterator policy included will break compilation.