TinyMCE V2 - Remove the height and width attribute from images in editor.

Hello,

I've been trying to programmatically remove the height and width attributes from the images via TinyMce

I've tried added a few things to to my initialization, but not of them seem to work.

It should be something simple like this:

 .AddSetting("extend_valid_elements", "img[class|src|id|alt]")

But that doesn't seem to remove the height and width attributes. 

invalid_elements only works on elements, not attributes.

image_dimensions removes the dimentions settings in the editor but not the code