Hotfix because I disabled hunting behavior by accident.

Full list of changes:

• Re-enabled hunting behavior (which is needed for monsters to follow you into winding corridors) which I disabled and forgot to re-enable when implementing 0.6.25 pathfinding fixes
• Blinding enchantment blinds for 2 turns (not 1)
• Fix: a monster which attacked and died (e.g. to thorns) doesn't try to alert its position and cause an error
• Performance improvement: don't create 2 game objects per terrain/feature
• Performance improvement: change "pixels per unit" instead of resizing sprites in code