Spiritus Astrum [P0-B14]: p1552: Towards Early Access

I have added nav objects to assist the player in moving around on board their capital ship, and I have fixed some issues with the ally and enemy AI.

A minor issue with the players missiles not registering collision with enemies under some circumstances was also fixed.

I have also done another complete retest of the third campaign, which uncovered some more, mostly minor bugs, as well as some balancing issues.

Most of these have now been fixed too. I should be ready to move on to the next phase of testing soon.