Core/Scripts: New ItemScript trigger, OnItemRemove
DB/Spells: Fix Thunderclap bugging Infected Wounds

By untaught. Closes #6291.
Update 2014_03_09_00_world_spell_group.sql
Merge pull request #11666 from kontownik/scripting_project

Core/Scripts: Introduce ItemScript::OnItemRemove, called when an Item is actually destroyed.