There should be drastically less ways to cause unprotected lua errors now, as
the LuaTable functions which were trivial to cause unprotected errors are now
protected. Unfortunately, they are protected in a pretty slow, terrible way
right now, but it at least works.
Also, set the atpanic function in lua to call a proper rust panic instead.
All lua types should now be at least somewhat usable from rust, if
incompletely so. Any lua value should be readable in Rust as a
LuaValue, pop_value should never panic except in internal logic errors.
kyren