title: Google Spreadsheet - MIX several column values
body: <p>Hello I have 3 or more columns in Google Spreadsheet like this:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>CITY</th>
  <th>SEASON</th>
  <th>COLOR</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>ROME</td>
  <td>SUMMER</td>
  <td>WHITE</td>
  </tr>
  <tr>
  <td>PARIS</td>
  <td>SPRING</td>
  <td>BLUE</td>
  </tr>
  <tr>
  <td>LONDON</td>
  <td>WINTER</td>
  <td></td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>What I need is a combination of all values in the 3 columns such as:</p>
  <ul>
  <li>ROME SUMMER WHITE</li>
  <li>ROME SUMMER BLUE</li>
  <li>ROME SPRING WHITE</li>
  <li>ROME SPRING BLUE</li>
  <li>ROME WINTER WHITE</li>
  <li>ROME WINTER BLUE</li>
  <li>PARIS SUMMER WHITE</li>
  <li>PARIS SUMMER BLUE</li>
  <li>PARIS SPRING WHITE</li>
  <li>PARIS SPRING BLUE</li>
  <li>PARIS WINTER WHITE</li>
  <li>PARIS WINTER BLUE</li>
  <li>LONDON SUMMER WHITE</li>
  <li>etc...</li>
  </ul>
  <p>Consider that columns could be 2 or more.
  Have any solution? Thank you!</p>