Redesign of equipment data structures

The current system with different classes for every type of equipment where i. g. a item has to be either a melee wapon or a ranged weapons does not work. Some items can be used as both, specifically for the Magic Orb of Illusionsist (Magic 1) stats in both categories are given.

The new system should only know one base class, e. g. Equipment and it contains different objects with the stats for the different usages of the items.