Spiritus Astrum [P0-B14]: p1550: Towards Early Access

I have added some improvements to the existing NPCAI and Companion AI systems, and improved the filtering of objects on the HUD, and I have made some improvements to the mission triggers in the third campaign.

I also completed another full retest of the third campaign. Even though I did discover some new bugs, the retest only took two days, since the campaign is becoming much more stable with each run.

I have already fixed many of the bugs discovered in the last test rung, they were mainly minor issues. I have also made some improvements to the game, such as line of sight checks when locking missiles onto targets, etc.

Thre are still some long standing issues with the project, which I will need to track down and fix eventually.