Long strings didn't work before because I hadn't implemented Lua's varint
decoding. It's an easy translation from the original C.
Int adding previously created a float because I always coerced to float.
Also an easy fix.
Still missing a lot of stuff. And I'm pretty sure the Rc handling code
is totally wrong.
And they don't have the Lua 5.0 optimization of an internal array,
but that's probably easy to put in.
This is a little pre-mature, since it's still in the "make it work"
phase of "make it work, make it fast, make it pretty".
But it was bugging me, and I'd have to ditch the raw strings and vecs
some day to add a GC anyway.
_