message: Making sure that cancelButton works with vertical tabs as well
diff: @@ -325,9 +325,11 @@ UI.tabs.tabWidget = function (options) {
  return box
  function addCancelButton (tabContainer) {
  - const extraTab = dom.createElement('td')
  + const extraTab = dom.createElement(tabElement)
  extraTab.classList.add('unstyled')
  + if (tabElement === 'td') {
  extraTab.style.textAlign = 'right'
  + }
  const cancelButton = UI.widgets.cancelButton(dom, onClose)
  extraTab.appendChild(cancelButton)
  tabContainer.appendChild(extraTab)
  