Made AI calculate using their strength instead of the total number of units, and made it calculate this only when it needs to instead of constantly
Merge branch 'master' of https://github.com/tmsbrg/SpelendLeren
Added new levels
Merge branch 'master' of https://github.com/tmsbrg/SpelendLeren

Conflicts:
	data/level/5.tmx
	data/level/6.tmx