Lua 5.1 work 2

[Roberto Ierusalimschy <roberto@...>]

Soon (today?) we will release Lua 5.1 work 2. The main change from w1 is
the fix of the GC bug related by Adam D. Moss (and fixed with his help).
It also has the fix of the '...' bug (that already had a patch).

(... bug: http://lua-users.org/lists/lua-l/2004-09/msg00113.html)
(GC bug:  http://lua-users.org/lists/lua-l/2004-09/msg00190.html)

Work 2 also has some changes in the C API to coroutines. The most visible
change is that now we can trace back a coroutine after an error:

  function f () a=a+1 end
  function g () f() end
  
  c = coroutine.create(function () g() end)
  
  _,msg = coroutine.resume(c)
  print(debug.traceback(c, msg))

(This is not finished yet.)

-- Roberto