Feature/delete multiple images 77123524

[finishes: #77123524]

I removed the logic to filter out the panamax-ui and panamax-api images from the list.. I think we need to discuss the best way to accomplish that. I will create a story to implement that feature.
I just noticed (not sure if we're doing this elsewhere), but a convention that I try to follow is that anything that takes the event as an argument is a handler, and I try to put 'handle' in the name. So, I'd call this handleObserverChange. If the handler function is overkill, you can do:
```
base.$el.on('change', base.options.observerSelector, function(e) { base.submitState(e) });
```