Hotfix demo.1.3

This update mainly concerns optimization and AI. It won't resolve all the performance issues, but I hope it's a step in the right direction.

• Fixed several scripts that progressively got more CPU-hungry into late game

• Reduced VRAM footprint

• Fixed AI recon platoons not attaching to combat groups and AA/HQ units getting stuck

• Slightly tuned down income settings to make losses more meaningful

• Added US forces as possible opponents in the Mobile Defense & Attack modes

Restart Steam to force it to check for updates.