[zerbdjry] Magnify vertically

For clicking on inline links in text, which tend to be thin horizontal areas, we would like a way to magnify a page in the vertical dimension only.

We would also like to maintain legibility.  Vertically stretched text is not.  We must only stretch whitespace between lines.  This is tricky if the text has multiple columns whose lines are not aligned.  Identify columns automatically or by analyzing layout (e.g., CSS).

This would also be useful for selecting text.

Fitts's Law.

Inspired by fat fingers on a mobile device.