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