Sticky blank string children

[Jeddf]

When making and then deleting a space after a word, an empty string element is appended on as a child of the contenteditable div.

These elements build up and only seem to be able to be destroyed if the whole div is destroyed, they even stick around after a submit event. This means they can build up indefinitely over time, not seen any performance hit in practice as yet but it seems like something that should be dealt with.

[wesleytodd]

I think this is actually related to the other one, the formatting function has a bit of funky behavior with multiple spaces. I would look at fixing the handling of that. Might be a good one to add unit tests for since you could probably mimic this all just by calling that method directly.