Scrolling position not preserved on window resize when zoomed most of the way out

[Robert Leach]

I thought that 2 fixes I made to some of the math in different branches would fix this issue, but it apparently has not.

If you select all but the first & last few rows/columns and zoom to selection, then resize the window larger, the scroll position shifts to the first row/column. The zoom level does not change.

What one would expect and what is intended to happen is that the current view stretches/expands to fill the larger window. No previously not-visible spots should be displayed when resizing finishes. No previously-visible spots should not be displayed when resizing finishes.

[Robert Leach]

It has been tested by Chris & I. Works.