|SOURCE|
[Common::GUIManager]
* Added SetFont so that all entities with fonts can share one font and will not
  have to manage it on a per element basis
* AddElement will set up the font if the element supports fonts
[Common::GUIButton]
* SetFont only accepts a TTF_Font pointer instead of the font path and point
  size
* GetName returns "Button"
[Common::GUIElement]
* Added pure virtual member function GetName to distinguish between element
  types (this should probably be an integer to make this comparison faster, but
  for now it isn't important)
[Common::FontCreator]
* The font is now set for the GUI manager instead of on a per-element basis