title: get last clicked tab index in jquery ui tab
body: <p>I am using JQuery UI tabs , to get the current selected tab i am using ui.index but i want an 
  index of last clicked tab. </p>
  
  <p>for example,
  initially tab 1 is loaded 
  after that if i click tab 3 then in show method i can fetch tab 1's index 
  and the same way if i click on tab 1 then i can fetch tab 3's index.</p>