Added a few more cases for quantized_dir.
First rough pass at lines.

Everything is correct, but the code is a little dirty.
Resizes handled properly.
Added bools to fill and/or stroke to rect shape.
Added module to encapsulate aspect ratio.

There isn't a reliable way to actually -get- the size of cells.
For now, we just hardcode 9:16. It's less wrong than 1:1.
Added h- and v- line special cases. Ignored them.
Doc update.
Propagated stroke and fill to ncurses rect ctor.
Propagated aspect ratio module.