What we can do here:
- patch our libxml2 copy to set xmlTreeIndentString to tab by default (is that what we need?); - remove use of deprecated symbols, including xmlThrDefTreeIndentString symbol; - merge that; - once 2.14 is out, we'll switch to save context API everywhere with xmlSaveSetIndentString(); - xmlNodeDumpOutput will have to be reimplemented locally, unless libxml2 people are willing to add an alternative that takes a save context;