add on board vector
	modified:   mahjong/game.cpp
	modified:   mahjong/game.h
add game_start_prompt
	modified:   mahjong/game.cpp
	modified:   mahjong/game.h
 update prompts and codes
	modified:   mahjong/game.cpp
	modified:   mahjong/game.h
	modified:   mahjong/player.hpp