update route and destination selection algorithms

[djgroen]

• The current algorithm crawls all routes for all individuals. This is relatively costly.

Possible alternatives

Recommende route list

• Generate, in advance, a list of recommended routes to all other locations for each location.
  • Needs to be done once per turn.
• Choose from destinations, accounting for route overhead using the best route.

Pruned destinations

• Prune destination list, removing non-interesting locations.
• Then generate routes towards the top destinations using a crawl algorithm.
• Awareness level should not be crawling-based, but e.g. based on distance or location type.

Destination only

• Don't use crawler, but first choose possible destinations within awareness criteria.
• Add a modifier indicating travel overhead.
• Only generate a route once the destination has been chosen, using A*.