add a "scale" option to the icongravity

[Neville Smythe]

> Wouldn?t you really need another property like ?iconSizing? which would have values of ?none? or ?clip? (current behavior), ?resize? or ?fill? (the current iconGravity option), and ?scale? (your proposal)?  I can think of situations where clip and scale would need the current positioning afforded by the gravity setting.

I think often the best option is “scale to fit” by which I mean scale the image down to fit the button keeping the same aspect ratio *if* it is too large, but leave the original image size as is if it will already fit, *do not* upscale, which can cause pixelation. It is neither the current ”resize”  nor the usual “scale to fit"