RFC: GUI Library Task Force

[Ch. A. Herrmann]

Basically, I like the suggestions, but want to clarify:

> * The library focuses on graphical *user interfaces* (ie,
>   buttons, menus, scrollbars, selection lists, etc) as
>   opposed to drawing and animation routines.

Many applications where GUIs are used require a canvas/scribble field
with the following basic functionality:

  - set a point in a particular color; if speed is an issue,
    mapping a 2D-array content to the canvas would be useful
  - read the relative mouse coordinates when a mouse
    button was pressed or released or the mouse was moved 
    with a pressed button  

Cheers
Christoph