Extend builtin with /spawn chat command

[SmallJoker]

This adds a /spawn chat command if it has not been added after one second after game start.

[Amaz1]

+1

[kaeza]

Why not outright register it?

Games that have a different approach to implement the /spawn command can just re-register it, and games which don't want/need it can just minetest.chatcommands.spawn = nil.

[SmallJoker]

@kaeza Thanks for this hint. Updated the commit.

[kahrl]

This command should require the teleport privilege.

[SmallJoker]

@kahrl Why? All spawn commands I've seen work without the "teleport" priv.

[kahrl]

Because it is a teleport?

In survival this lets you get out of a sticky situation and teleport into a most likely safe area (like /kill as in #396, but without death penalties such as losing items). This makes it a cheat and therefore it should require a cheat privilege such as "teleport".

[Calinou]

We already have /home and /sethome which require just the home privilege.

The solution is to create a spawn privilege in order to use /spawn.

[SmallJoker]

@kahrl I see what you mean, a spawn privilege would be a better soulation in this case, as @Calinou said. But it's again a privilege with a single usage, a setting in minetest.conf would be a better soulation then.

static_spawn_command = true

[ShadowNinja]

A /die command would be good. It wouldn't require any special privileges because you would receive any death penalties that the server imposed, such as losing items to bones.

[SmallJoker]

Dying is not what the most spawn commands target to do. Also, that would be an other PR.

[BlockMen]

I agree with @ShadowNinja that a /die command would be better. Some more thought on that here:
http://irc.minetest.ru/minetest-dev/2014-10-02#i_3959299

[SmallJoker]

At least 2 devs disagree. Closed.

The /die command is an other topic.