Functional wand upgrade item system. Committing prior to refactoring a bit.

Some of these changes (mostly the Wand private -> protected) may end up
being unnecessarily, but I'll just keep them anyway.
Huge refactor to wand trader attributes.
Skip NPC's when looking for Gather targets.
Make NPC's generally untargetable.
Fix /configure command wiping spells.
Adding a wand can set particle or sound effects.
Another fix to wand spell and material loading.
Don't unload NPC Mage data on save.
Grr stupid material constant inconsistencies! (Fix ICBM icon)
Fix wand upgrade items.