Improvements for the AI's gameplay

Villagers
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 - Don't collect resources in hazardous areas / send the military to clear them out
 - Send military task forces to guard strategic resources / tower them
 - Don't build in hazardous areas
 - Build more gates in walls to prevent lock-ins
 - Prefer to build castles and towers near the water/thin places
 - Create more trade cogs and trade ships

Military
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 - Avoid fighting in hazardous areas / prefer fighting in range of own castles
 - Coordinates reaction to attacks on units (during march, ...) (including attacks by towers/castles)
 - Disable scouting if the "all visible" option was selected.

Ship
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  - Transport ship can deliver villagers to another islands
