New tile visibility framework!
 - Differentiated attackable from visible tiles per Civ V
 - Tiles 1 step out of bounds of visibility are visible if they're higher than current tile
 - Higher tiles can be visible beyond non-visible, hidden tiles

Damage bonuses are additive, per Civ V, not multiplicative

Resolved health bar overflow problems

Preparation for Tactical AI Rework: analysis map, domination zones  - By vegeta1k95