Split up tile drawing code.
Use windows for relative drawing.

This cleans up the graphical code a tad.
Optimise the tile drawing code.

We now just use ClrScr to fill in the tile background, and draw
the frame afterwards.

Some window hacks were required to make this work properly...
Clean up code, and screen too.
Remove useless Key variable.
Factor out end-game strings into an array.

Less redundancy, yeah!!
Add gitignore.
Add basic Makefile.