Extend the .inx RELAX NG schema to allow the appearance="minimal" option that Jon Cruz recently added. All .inx files now validate against the schema again.
Format the .inx RELAX NG schema, to make it more readable, and to allow diffs against it to be comprehensible.
All extensions are now propper XML files with a namespace and all validate against the new inkscape.extension.rng RelaxNG schema.