When taking a large screenshot after a small one, or vice versa, the editor window opens to a size not appropriate for the image. Either there is a lot of wasted space, or the image has to be scrolled.
This patch causes the editor form to size itself appropriate to the incoming capture. It has a minimum size (hard-coded to 480x360) to avoid ridiculously small window sizes for very small captures.
This probably satisfies feature request IDs: 3152489, 3302312, 3195194.