Make faction base location affect raid direction

[b0rsuk]

I can't spot the pattern in raids. The direction they come from seems semi-random, but it doesn't make much sense.

In my game Knuckleduster Men have the base to the east and slightly to the south. The Wild Executioners have the base to the southwest. The last raid was Knuckleduster Men, sappers from the WEST. The Wild Executioners often came from the EAST. Most raids and caravans in my game come from the east, from the same spot near a mountain.

Then I loaded game and spawned a bunch of raids from various groups and couldn't find a pattern.

I think the direction they come from should be strongly affected by where they have their base, plus minus some randomization value. This should also affect caravans and visitors (travellers, visitors less so, especially if they're passing through).

If this is implemented, it will add a small strategic factor to choosing landing site.