Additional Missile launch tubes do not yet need to be exterior

[darloth]

More of a Todo: than a bug, but they're meant to require exterior hexes so that constructing the perfect alpha strike missile launcher is a little more difficult than just sticking lots of tubes in it.

Sadly, I'm currently lacking in time to work out and code up something that checks a module is exterior instead of just the core - it's not hard, I just haven't done it yet, so here's an issue to remind me or others.

[DaloLorn]

Whatonearth--

Missile launch tubes?

... returns to commit analysis