Error handling

[molnarm]

Added a callback for error handling, e.g. to display a message instead of the failed item (that's what I'm using it for in our app).

Will get called for error events on:

• img tags: will happen if image fails to load or decode (unknown format). Note that the preloading will fail silently, because the error will be thrown again when displaying, and it makes more sense to handle it when the item is expected to be displayed.
• source tags in audio or video items: if the media item fails to load or play (unknown format)
• iframe tags: any error. I didn't test this one.

The callback gets container and activeItem like all the others already present, plus the error itself.

I'm using Windows so I didn't commit the build outputs because they are different from yours (backslashes etc.). Let me know if I should change something else.

[henrygd]

Thanks, I'll review it in the next few days

Edit: Looks good, I'll get a new version out this weekend.

[henrygd]

Added in 1.1.7.

I did remove the iframe listener because it's not as simple to implement as the others. If users need to add their own logic for iframes, it can be done with onOpen or onUpdate.