lua 5.1 ==> 5.2

============》第一条：

默认情况下，lua5.2中没有 【luaL _openlib】api了，这是5.1中的API，实现于【lauxlib.c】中。至于替代方案，可以是这样：

luaL_openlib(L, "mylib", mylib, 0)变成

//Pushes onto the stack the value of the global name.lua_getglobal(L, "mylib");if (lua_isnil(L, -1)) {  lua_pop(L, 1);  lua_newtable(L);}

//Registers all functions in the array l (see luaL_Reg) into the table on the top of the stackluaL_setfuncs(L, mylib, 0);

Pops a value from the stack and sets it as the new value of global name.lua_setglobal(L, "mylib");

============》第二条

lua5.2中【luaL_register】已经废弃了，因为会污染全局名字。以下是lua5.2官方文档的说明： 

• Function luaL_register is deprecated. Use luaL_setfuncs so that your module does not create globals. (Modules are not expected to set global variables anymore.)

一般建议这样子写：

lua_newtable(L);luaL_setfuncs(L, mylib, 0);return 1;