Don't reset zoom state when loading if old and new image size is the same.
I believe the title is fairly self-explanatory.
I was working on a large set of 32x32 icons and doing a lot of load / save.
Each time I loaded, the zoom display was removed and I had to hit M to bring it up again.
It would be more convenient if GrafX2 preserves the zoom state in the case where the newly loaded image is the same size as the previous image.