Improve multimedia resolution with more box-drawing characters

[dankamongmen]

Right now, we get 2xV/1xH resolution when scaling multimedia, by use of half-cell drawing characters. I think we ought go further. If we immediately went to 2xV/2xH, we could use the quadrant-cell characters. This would perfectly handle any 2x2 render that uses only 2 colors. The problem of course would be when 3 or 4 colors are present in a 2x2 block. In that case, we could use interpolation or something.

[dankamongmen]

See #137

[dankamongmen]

This might be useful for things like text, see #116 .

[dankamongmen]

This was accomplished with #667 and #648. We're good!