Murgol Lair now has a stair up on level 1

Ritches in the Ritches tunnel now have only 40% fire resist
Trap damage randomization changed so they do not get 100 or more damage at level 1


git-svn-id: http://svn.net-core.org/repos/t-engine4@2507 51575b47-30f0-44d4-a5cc-537603b46e54