xml2 1.3.6

• Now compatible with libxml2 2.12.0 and later (@KNnut).

• Fixed format string issues detected in R-devel.

• Remove unused dependencies on glue, withr and lifecycle (@mgirlich).

• print() is faster for very long xml_nodeset inputs (#366, @MichaelChirico).

• xml_attr(), xml_attrs(), xml_double(), xml_integer(), xml_length(),
  xml_name(), xml_path(), xml_text(), and xml_type() no longer use
  S3 dispatch but instead dispatch in C, leading to considerable performance
  improvements in many cases (@mgirlich, #400).

• xml_find_int() analogous to xml_find_num() for returning integers
  matched by an XPath (#365, @MichaelChirico).

• xml_serialize() now includes the document type so that xml_unserialize()
  works also for HTML documents (#407, @HenrikBengtsson).