Pretty terrain

I re-wrote the draw routines for the DNA. Now all 3 open-reading frames are shown and also the amino acids align nicely centered inside the ORF marks. Found a way to sample key-presses less oftern which makes navigation easier. Fixed a few bugs as well. Next up is to really tackle the user interface/game screen which I have been putting off. I needs help screens or a permanent way to see the codons associated with each amino acide. Also need to show which enzymes have been bought and what they do.  Last work on gameplay. Then package game.

Latest version is attached.