Let the Spring.GiveOrder callout family accept nil params/opts

[sprunk]

• Spring.GiveOrder(cmdID, {}, 0) is required to correctly give a parameterless option.
• you cannot skip either the params or the opts args.
• you can pass a fake numerical parameter arg to avoid making a table, e.g. spGiveOrder(cmdID, 0, 0), but this is only correct if a command is strictly parameterless (will have a behaviour difference if it can accept either 0 or 1 arg).
• the request is to let opts accept nil and default to 0, and for params to also accept nil and default to no params. This would let devs give commands like spGiveOrder(CMD.STOP).
• don't forget to document it.