Adding new images resets the current image index

[rraziel]

When modifying the images array (e.g. adding 3 new images to it), the current image index is lost.
While this may be fine - as the array may contain entirely new images unrelated to the previous batch - there is seemingly currently no way of saving the current index then re-applying it, as doing it via setActiveImage right after modifying the array appears to be too early.