make.graphic.viewport boolean
make.graphic.viewport Use tables in HTML to make viewports for graphics

## Description

The HTML img element only supports the notion of content-area scaling; it doesn't support the distinction between a content-area and a viewport-area, so we have to make some compromises.

If make.graphic.viewport is non-zero, a table will be used to frame the image. This creates an effective viewport-area.

Tables and alignment don't work together, so this parameter is ignored if alignment is specified on an image.