message: Improve XML/HTML markup syntax highlighting
  Correctly recognize tags with : or - in them too.
diff: @@ -153,7 +153,7 @@ private:
  };
  -std::wregex RE_HTML_MARKUP(LR"(<\/?[a-zA-Z]+(\s+[-\w]+(=([-\w+]|"[^"]*"|'[^']*'))?)*\s*\/?>)",
  +std::wregex RE_HTML_MARKUP(LR"(<\/?[a-zA-Z:-]+(\s+[-:\w]+(=([-:\w+]|"[^"]*"|'[^']*'))?)*\s*\/?>)",
  std::regex_constants::ECMAScript | std::regex_constants::optimize);
  // php-format per http://php.net/manual/en/function.sprintf.php plus positionals
  