That's... that's it, really. Also, there's a new warning in `sol::as_table`, because people kept trying to slap it on class bindings and that's not what it was for, damnit.
Adds documentation for the new feature
Removes usages of "sol::bond" in documentation, because that was supposed to be "sol::tie"
I really don't want to spend time trying to figure out how to slim down these templates...