Simple way to prevent certain content types from using a wysiwyg editor

This allows an administrator to disable the wysiwyg editor on select content types by adding a no_wysiwyg=true param to the content type.

This is needed because CKEditor sometimes thinks it's better than the person writing the content and rewrites the HTML.
If we choose `no_wysiwyg`, then we should just check for its presence.  Do we really need the second check?