Cluck quest fix

The fixes the Cluck! quest, where the Continue button is disabled when
it should be enabled.

The SpecialFlags field was set to 1, when it should be 0.
Quest 5381 Hand of Iruxos not completable fix

This fixes the issue where the Quest 5381 Hand of Iruxos is not
completable, due to the demon box not appearing as loot after killing
the
NPC (after breaking the crystal with the pickaxe)

The spawn chance for the demon box in the creature_loot_table was set to
-100 (minus 100 percent)
Merge pull request #6 from Chuck5ta/Rel19_Newbuild

Cluck quest fix, plus Quest 5381 Hand of Iruxos not completable fix