Better handling of size limit when resizing a table

Avoid silent conversions from int to unsigned int when calling
'luaH_resize'; avoid silent conversions from lua_Integer to int in
'table.create'; MAXASIZE corrected for the new implementation of arrays;
'luaH_resize' checks explicitly whether new size respects MAXASIZE.
(Even constructors were bypassing that check.)

lua.h

@@ -268,7 +268,7 @@ LUA_API int (lua_rawget) (lua_State *L, int idx);
 LUA_API int (lua_rawgeti) (lua_State *L, int idx, lua_Integer n);
 LUA_API int (lua_rawgetp) (lua_State *L, int idx, const void *p);
 
-LUA_API void  (lua_createtable) (lua_State *L, int narr, int nrec);
+LUA_API void  (lua_createtable) (lua_State *L, unsigned narr, unsigned nrec);
 LUA_API void *(lua_newuserdatauv) (lua_State *L, size_t sz, int nuvalue);
 LUA_API int   (lua_getmetatable) (lua_State *L, int objindex);
 LUA_API int  (lua_getiuservalue) (lua_State *L, int idx, int n);