On a test site I am working on I am trying to add Slimbox since the Sienna plugin does not work on 0.9.9 and to make it work I need to add the following code to all images I want to use Slimbox on: rel="lightbox".
However, if I edit the code of the page on which the images are the CKeditor constantly removes the rel="lightbox". I have already set the HTML Purifier tidy level to "none" to not remove my code but it keeps getting removed.
So, I figured I might have to change the CKeditor output and searched with a google a bit. I found that to change the output you need to change the CKEDITOR.htmlWriter but I can not find such a file in the plugin. Since this was converted to a Sienna plugin should I change the output elsewhere? I checked all files (except images) to see if any of those files contained output but I simply do not see it.
Any help is very much appreciated 
PS: I have big issues to get used to this editor, my text/links/code anything always is completely screwed up 
<img src="http://www.armaholic.com/datas/thumbs/green-sea-battalion-uniforms-version-03-preview_4.jpg" alt="green-sea-battalion-uniforms-version-03-" />
