I sorta asked this in reply to another question, but I still don't know how
to do it.
Is there a way to traverse the entire globals/registry and get the
strings/symbol names out? (only top level stuff is needed, not a deep
traversal) We're setting tables and functions to nil and it seems that not
everything is being garbage collected. I want some way to find out what lua
is still holding references to so I can clean them up. What are the ways to
do this?