So this seems to works for swiss army:
Added that function towards the top, then I called it like this at the bottom of inter_slide.prototype.changeimg :
It seems to work just fine on manual and automatic change, except for the fact that, when changing manually, I get two alerts: One alert before the change which gives me the starting image, and another after the transition which gives me the finishing image...
onImageChange(this.nextimgidx+(bool? 1 : 0));
I'm sure it won't make that much of a difference when queuing animations; so as long as I check the animations' statuses each time it activates; But I'd much rather do without the redundancy; going to keep working...