Allow setting targets for a group as soon as they spawn, instead of waiting for them to get within a "intel response distance."

- New setting to prevent AI from leaving the formation to engage targets.
- Show what friendly groups are attacking on the map.
- Make the battle area border more visible.

- Target selection improvements:
-- Find best target on the first run, reducing annoying target switching.
-- Make groups prioritize targets that have fewer units already attacking them.
-- Configurable limit on how many groups can be targeting the same group. This helps keep the battle a bit more spread out rather than condensing into a single spot.
-- Allow unengaged units that are closest to possible targets choose their targets first, resulting in less random looking target selections.
- Change the patrol endpoint to MOVE instead of SEARCH AND DESTROY, removing the pointless wandering around at the end of the patrol route.
- Fix intel grid appearance - remove grey blocks, add border instead.

* AI configuration dialog with options for:
- Group patrol and attack formation.
- Movement speed, including a custom "smart" mode where AI runs in open areas and moves slowly in cover.
- Allowing last remaining units from a wiped out group join a new group nearby.
* More forest detection improvements, again.

Increase max size of spawned groups to 8

Use separate spawners instead of spawnpoints

Increase sensitivity for forest detection.
Decrease flanking distance for positions among buildings the same way as with forests.
Make initially spawned groups keep formation more.

Add fog slider
Add visible battle area border to preview

Fix response distance fields in advanced config behaving weirdly.