Further detail

Added a bunch of stuff, like different Obect types. Again, I am mainly
doing the frames and adding everything in later on. Just thinking about
what I will need.
Beginning of the Attack

Added methods to handle receiving and dealing damage.
Added possibility to upgrade inventory.
Revised Calculation of the Experience Cost for a levelup.

Changed design for different kinds of inventories, so only one class it
needed for all the different stuff like Spellbooks, Armor slots and so
on.