more HUD mockups

Created mockups showing the ui in the following states:
*human-no-items
*human-with-items
*werewolf

Also included images of the HUD items: keys and potions. When a player
gets a key, it fills up the slot. When the player gets a potion, it
fills up its slot. This forces the player to use the cauldren and not
just dump in potions all at once.