v0.04 Build 403

Initial configuration of inventory gui
v0.04 Build 404

Added the inventory GUI
- Activated by clicking on the inventory button
- Picking up items puts them in empty slots
- To use an item (Like the key in a door) the key has to be in your hand
- By clicking on an item if it isn't in your hand it is put in your
hand. If the item is already in your hand it is removed

Issues:
Currently clicking on the GUI also makes the player move to that
position, this will be fixed when I have access to a touch device so I
can test out a fix.