added bin files and removed gvv warnings
remove warnings on 2nd boot, use graph_frame for blitter
modify test engine with smaller sprites
add simple modes

simple modes are modes based on a 64k framebuffer
- text modes 80x25 132x75 characters
- graphical modes : 800x600, 640x400, 320x240, 320x200, with different
color depths
- includes a demo of text modes and graphical modes