ModelShifter

This is a rather small release with some small improvements and a lot of bugfixes:

• Added a new /model command to quickly change or disable your model
• Nametags will now be positioned depending on the model
• The fire on burning players will now be scaled depending on the model
• Reworked the walking animation of the wither model
• Fixed the scale of models in the inventory GUI
• Fixed texture issues on the baby model