Keyboard is not reactive

[Dhebug]

From Lukas:
Now and then the typed characters do not register properly

[peralmered]

How often is the keyboard polled? Because, I mean, even in BASIC, if I type at my normal speed, characters go missing!

[Dhebug]

It's kind of complicated, but the main problem is that the code was not correctly reading the keyboard in the IRQ, so in some situations (during fades or animations) the event could be missed.

In version 0.8.6 I implemented a single buffer key we should at least solve that problem.