Turn 0 artillery

[Mobhack]

The + option for the initial stonk has been there a decade or more, I think I added it to the DOS version, but it may have been in the original SSI code. Been so long, I cannot clearly recall. The original stonk was limited to one fire mission, though.

Now it works for the programmed fires - ie you can plot fire on each turn, hit + and plot again, etc if you have the full game. The AI also will use a programmed fire mission at times in the advance or assault.

However it's getting its plot a little wrong for under command batteries, which I'll need to investigate further. It may be a scenario thing.