High Scores and Tidying

Think I'm on the final stretch for this little project.

I've now added a high score table ( it's volatile, so will start afresh each time you come to the game.. I may fix this. )
The method for adding high scores matches the odd controls, and I think it works well. I've been trying to limit the controls to one or two buttons only as an interesting challenge. I think it works well though.

The remaining parts are just wave intro/outro sequences, then some code clean-up before I put the project up.