RemoveHtmlSelectors - Preserve ID's

Hi All, firstly thanks for the library - it's saved me a great deal of time!

At the moment, the library has the option to either keep all HTML selectors or remove them; but I think there might be cases where it would be useful to have the option to set class and ID selectors individually.

In my case, I originally had this option set to (to keep the output lean) but have now had to enable it since the code base now uses in-page links (which were being broken due to the ID attribute being removed from target sections). If the library allowed id/class attributes to be preserved independanly then I'd be able to strip out just the class attributes.