Dizzy 1 Prototype (Amiga) - controls fixed.

This is a small update to the game.

I used my new experience with the Timer function to improve joystick polling, away from the broken gameport function. It is now activated every 3 jiffies, which means the screen refresh is fast, but the images are still flickering. Spent ages fixing Dizzys' arms moving up and down, and the repeated movement left or right still needs fixing. 

But everything feels better than it did, and the game no long feels so janky to play it.