Rewrote the window and window functions
Changed function signature fow window creation
Added new imports and a multimethod for wrapping of Java Color class
Added a new Renderer record type

  - The new type is used for rendering graphics in a window
Rewrote window protocol and recor to use new Renderer

  - Also added a new render function, to do the actual page flip between
    the buffers
Added internal functions used to make a color transparent at runtime
Added a sprite record and a function to load sprites from image file
Added spritesheet support

  - A spritesheet has its own record and can be loaded from image file
  - The images within the spritesheet can be extracted into seperate sprites