dcp_inspect: Internal cosmetics
dcp_inspect: Reel completeness (SMPTE error, Interop hint)
dcp_inspect: Bump version
dcp_inspect: Handle multiple default namespaces

See https://github.com/sparklemotion/nokogiri/issues/885 for details

This adds

  Nokogiri::XML::Document#collect_all_namespaces_href_keys
  Nokogiri::XML::Document#collect_all_namespaces_prefix_keys

which allow to actually collect all of a document's namespaces
and namespace prefixes.
dcp_inspect: Internal changes related to fdecae6
dcp_inspect: Report app execution time