More rent changes

Rent cost for trolls and orcs (torcs that is), has been reduced by a
factor of 1.41, making it identical to citizen rent for whities.

Rent cost for zaugurz orcs has been increased by a factor of 1.41,
making it identical to orcs/trolls/bns.

Zaugurs and BNs still have a free allowance before they start paying
rent.

- Ilie