Changed studying at Kakuzu to be easier depending on Game Difficulty setting.

locations/kakuzu.qsrc

@@ -95,7 +95,7 @@ if $ARGS[0] = 'mansion1':
 			if srodstvo = 0:srodrand = rand(1, 5)
 
 			'You concentrate energy in the sheet of paper. You feel that you are spending a huge amount of mana for this action.'
-			srodstvo += rand(1, 10)
+			srodstvo += rand(9-(2*difficulty), 10)
 
 			if srodstvo < 100:
 				'You get tired and sweat like a horse, but your effort was not enough.'