Briefly futz around with Lair endings

 * Fix up a previous half-done dog/bear end edit, bringing back raiju
   to the vault and randomly scattering in more hell hounds / raiju.
   Very lightly and randomly up'd the loot a small bit, too.
 * Only put one wolf spider in the fast poisonous monsters end,
   since the boss bundle is mean enough as is. The slot joins three
   others in being a black mamba, a spiny frog, a yellow wasp, or nothing.
 * Tweak and add in some comments.