v0.977: Terrain Destruction and Random Artifacts

It's time for another release. Terrain destruction has been added- when the fighting gets too intense, the scenery might start getting wrecked. The resulting fires will burn any mecha passing through that area, and smoke limits line of sight.

In addition, there are now unique random artifacts... or at the very least, unique random melee weapons. More types of random items will be included in future releases.

Here's the complete list of changes:

• Added random artifact generator
• Added mystery missions
• Fire and smoke may result when terrain is damaged
• Attacks may cause damage to terrain
• Added AreaEnchantments
• Fixed bug with random MissionText
• Scenario builder automatically adds QOL reporter to cities
• Added message log