implement lua_thread_abort, add lua_thread_yield_state func, and fix lua_thread_resume_state to use protected mode
#include "lua_config.h"
#include <lua5.1/lauxlib.h>
err_t lua_config_load (struct nexus_lua *lua, const char *path, struct error_info *err)
{
// just use luaL_loadfile and translate the error code
if (nexus_lua_error(lua->st, luaL_loadfile(lua->st, path), err))
// XXX: pollute the stack
return ERROR_CODE(err);
// execute it
// XXX; error handler with debug info
return nexus_lua_error(lua->st, lua_pcall(lua->st, 0, 0, 0), err);
}