Use RawElement instead of UIElement in editor view, and instead of ContainerElement in data view

[Jules-Bertholet]

This PR ensures that the proper element types are used when constructing the data and editor views. From limited testing it seems that this could fix (edit: nope) #20, but I've never been able to reproduce that consistently so I'm not sure.

[tony]

This seems to work for me! Nice!

What exactly is this changing? Does this change the HTML that's ultimately saved in any way?

For #20, I wasn't able to reproduce the issue on master or here, so I'm uncertain about that.

[Jules-Bertholet]

Unfortunately, following some more testing it appears that this PR doesn't fix #20 after all. Of note: I've only seen #20 on Firefox, have never been able to reproduce it on a Chromium or WebKit browser

[tony]

@Jules-Bertholet Regarding this not fixing #20, do you think this is still necessary?

Side note: I will publish v28 today

[Jules-Bertholet]

@tony I honestly have no idea. The PR makes the plugin use elements that are more in line with what the CKEditor documentation recommends, but I'm not sure what (if any) effect this actually has on anything.

[tony]

@Jules-Bertholet Can this be rebased?

[tony]

I forgot that this PR may not actually work. @Jules-Bertholet If you are of that belief, would you like to close this and perhaps offer some detail on the bug, your solution and the shortcoming in case someone else wants to PR?