This allow a lot more characters to fit on that tiny screen...

ref #41

That's a lot of code for such a small change, but there's a big difference
between 5 pixels and 4 pixels: 4 pixels requires compositing.

This was mostly lifted from my "tihello" example, but it required significant
adjustments.

This commit also introduces a font management system. A lot of fonts are
available online, but sources aren't always clear so to avoid copyright
landmines, I re-created my first 5x7 font from scratch.

As it is now, this resulting ROM gets "Collapse OS>" to be displayed on the
LCD screen. Much work still left to do.

ref #41