Thicker bars, better letters

Thicker bars, better letters
Aparently there's a limit to how thick an OpenGL line can be, so to get
lines of sufficient thickness I switched to drawing large polygons.

Also to help with getting the text and sequence view to line up correctly,
I pushed all the font letters down so they're centered at the midline.

There's also more work that needs to be done for z-order, the window
connections z is currently just hardcoded.

Also I made my hacked vector  A, G, and Cs look a little bit better.