message: Fix highlighting of HTML tags with - in attributes
  Fix the regex for highlighting HTML tags to allow - in attribute names.
  In particular, this fixes highlighting for code using AngularJS or
  commonly occurring data-* attributes.
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
  