Remove 'reset to Dropbox' button since it's deprecated

Remove experimental rendering (experiment unsuccessful)

Testing: Damage animations on damaged units

chore: Battle animation readability

Slightly faster animation

Units sprites move towards the enemy they're attacking

By WhoIsJohannes:
- Performance improvements 
- Civs should not go all-out war if they're weaker than barbs 
- Don't leak other civs in the game through LineChart colors. 

Avoid first contact alerts for dead City-States  - By SomeTroglodyte