Console framework refactored

Hi all,

I've refactored the console framework for better maintainability & a better separation of responsibilities.

I've introduced a new driver that implements textscreens. A textscreen is a rectangular output device for characters. There is supported for a bufer textscreen ontop of the actual device screen, and also a scrollable textscreen. A textscreen only know how to place characters at a given x,y location.

A console is build on top of a textscreen. It adds input & outputstreams, the knowledge of newline, backspace & tab characters and handles certain keyboard & mouse events.

If you encounter any problems in the system, please let me know.

PS. Currently the cursor is still missing, this will follow shortly.

Ewout