@a, @p or @r in player and console-sent commands

CMDBOOK-2312 - Reported by killjoy1221

This works in vanilla, but bukkit has yet to implement it. You could do "/give @a fish" to give everyone some fish. You could also do "/slay @r" to kill a random player.

Currently, this is impossible without using commandblocks.

首先定位玩家和控制台发送的命令的解析与执行入口点，然后跟踪命令参数的解析方式。将当前行为与所请求的选择器 @a、@p 和 @r 进行比较；当这些选择器能够用于相关命令且无需命令方块时，即视为完成。

由索引模型根据 Issue 内容生成。