Display road per-turn costs in the stats

Modding: Cloned units' triggers happen after the data is copied to them

By RobLoach:
- modding: Allow attack sounds by unit name 
- modding: Add a Researched Technologies Countable
- Fix `<on [difficulty] or higher/lower>` Conditional 
- Fix Worker Improvement Automation Checks 
- civilopedia: Only show active Victory Types 

Link historical Great Person names to Wikipedia - By SomeTroglodyte