message: Fix quotes handling in HTML syntax highlighting
  Properly check content of quoted strings instead of eating everything up
  to the last quote character in the text.
diff: @@ -138,7 +138,7 @@ 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
  