Add context menu item for images to quickly edit class name

I would like to be able to quickly change the stylesheet class within the IMG tag by right clicking on the image within CKEditor.

For instance, let's say I want to add a border to an image, I use class "bord1". So I would right click on the image, and select "Add border" from the context menu. class="bord1" would then be added in the IMG tag.

Of course, I want to be able to remove the class, or change it to "bord2" at any time by using the context menu.

Another example would be to align the image by changing its class, not by adding style="float:left" like CKEditor does by default. I might not need to use the context menu for this, but simply change the behavior of the align setting from the image properties dialog.

Ideally, since my IMG tags are all wrapped by a A tag, I need to apply this class to the A tag, not the IMG, but that's another issue.

I had a look at the API, read this article on the forum, but I still don't get it.

Any help appreciated !